TWILIO INC, 10-K filed on 3/1/2018
Annual Report
Document and Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Jun. 30, 2017
Jan. 31, 2018
Common Class A
Jan. 31, 2018
Common Class B
Entity Registrant Name
TWILIO INC 
 
 
 
Entity Central Index Key
0001447669 
 
 
 
Document Type
10-K 
 
 
 
Document Period End Date
Dec. 31, 2017 
 
 
 
Amendment Flag
false 
 
 
 
Current Fiscal Year End Date
--12-31 
 
 
 
Entity Well-known Seasoned Issuer
Yes 
 
 
 
Entity Voluntary Filers
No 
 
 
 
Entity Current Reporting Status
Yes 
 
 
 
Entity Filer Category
Large Accelerated Filer 
 
 
 
Entity Public Float
 
$ 1,678 
 
 
Entity Common Stock, Shares Outstanding
 
 
70,176,391 
24,054,845 
Document Fiscal Year Focus
2017 
 
 
 
Document Fiscal Period Focus
FY 
 
 
 
Consolidated Balance Sheets (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Current assets:
 
 
Cash and cash equivalents
$ 115,286 
$ 305,665 
Short-term marketable securities
175,587 
Accounts receivable, net
43,113 
26,203 
Prepaid expenses and other current assets
19,279 
21,512 
Total current assets
353,265 
353,380 
Restricted cash
5,502 
7,445 
Property and equipment, net
50,541 
37,552 
Intangible assets, net
20,064 
10,268 
Goodwill
17,851 
3,565 
Other long-term assets
2,559 
484 
Total assets
449,782 
412,694 
Current liabilities:
 
 
Accounts payable
11,116 
4,174 
Accrued expenses and other current liabilities
53,614 
59,308 
Deferred revenue
13,797 
10,222 
Total current liabilities
78,527 
73,704 
Long-term liabilities
11,409 
9,543 
Total liabilities
89,936 
83,247 
Commitments and contingencies (Note 10)
   
   
Stockholders' equity:
 
 
Preferred stock, $0.001 par value, 100,000,000 shares authorized, none issued
   
   
Common stock, $0.001 par value per share: Authorized shares 1,100,000,000 as of December 31, 2017 and 2016; Issued and outstanding shares 93,969,796 and 87,248,548 as of December 31, 2017 and 2016
94 
87 
Additional paid-in capital
608,165 
516,090 
Accumulated other comprehensive income
2,025 
 
Accumulated deficit
(250,438)
(186,730)
Total stockholders' equity
359,846 
329,447 
Total liabilities and stockholders' equity
$ 449,782 
$ 412,694 
Consolidated Balance Sheets (Parenthetical) (USD $)
Dec. 31, 2017
Dec. 31, 2016
Preferred Stock
 
 
Preferred stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Preferred stock, authorized (in shares)
100,000,000 
100,000,000 
Preferred stock, issued (in shares)
Common Stock
 
 
Common stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Common stock, authorized (in shares)
1,100,000,000 
1,100,000,000 
Common stock, issued (in shares)
93,969,796 
87,248,548 
Common stock, outstanding (in shares)
93,969,796 
87,248,548 
Consolidated Statements of Operations (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Consolidated Statements of Operations
 
 
 
Revenue
$ 399,020 
$ 277,335 
$ 166,919 
Cost of revenue
182,895 
120,520 
74,454 
Gross profit
216,125 
156,815 
92,465 
Operating expenses:
 
 
 
Research and development
120,739 
77,926 
42,559 
Sales and marketing
100,669 
65,267 
49,308 
General and administrative
59,619 
51,077 
35,991 
Charitable contribution
1,172 
3,860 
 
Total operating expenses
282,199 
198,130 
127,858 
Loss from operations
(66,074)
(41,315)
(35,393)
Other income (expenses), net
3,071 
317 
11 
Loss before provision for income taxes
(63,003)
(40,998)
(35,382)
Provision for income taxes
(705)
(326)
(122)
Net loss
(63,708)
(41,324)
(35,504)
Deemed dividend to investors in relation to tender offer
 
 
(3,392)
Net loss attributable to common stockholders
$ (63,708)
$ (41,324)
$ (38,896)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)
$ (0.70)
$ (0.78)
$ (2.19)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)
91,224,607 
53,116,675 
17,746,526 
Consolidated Statements of Comprehensive Loss (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Consolidated Statements of Comprehensive Loss
 
 
 
Net loss
$ (63,708)
$ (41,324)
$ (38,896)
Other comprehensive income:
 
 
 
Unrealized loss on marketable securities
(598)
 
 
Foreign currency translation
2,623 
 
 
Total other comprehensive income
2,025 
 
 
Comprehensive loss attributable to common stockholders
$ (61,683)
$ (41,324)
$ (38,896)
Consolidated Statements of Stockholders' Equity (USD $)
In Thousands, except Share data, unless otherwise specified
IPO
Common Stock
Common Class A
USD ($)
IPO
Additional Paid-in Capital
USD ($)
IPO
Common Class A
IPO
USD ($)
Follow-on Public Offering
Common Stock
Common Class A
USD ($)
Follow-on Public Offering
Additional Paid-in Capital
USD ($)
Follow-on Public Offering
Common Class A
Follow-on Public Offering
USD ($)
Preferred Stock
Convertible preferred stock
USD ($)
Common Stock
Common Class A
USD ($)
Common Stock
Common Class B
USD ($)
Additional Paid-in Capital
USD ($)
Accumulated Other Comprehensive Income
USD ($)
Accumulated Deficit
USD ($)
Common Class A
Common Class B
Total
USD ($)
Beginning balance at Dec. 31, 2014
 
 
 
 
 
 
 
 
$ 111,691 
 
$ 17 
$ 8,920 
 
$ (89,434)
 
 
$ 31,194 
Beginning balance (in shares) at Dec. 31, 2014
 
 
 
 
 
 
 
 
42,482,490 
 
17,446,051 
 
 
 
 
 
 
Increase (Decrease) in Stockholders' Equity
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Net loss
 
 
 
 
 
 
 
 
 
 
 
 
 
(35,504)
 
 
(35,504)
Issuance of stock
 
 
 
 
 
 
 
 
125,448 
 
 
 
 
 
 
 
125,448 
Issuance of stock (in shares)
 
 
 
 
 
 
 
 
11,494,249 
 
 
 
 
 
 
 
 
Exercise of vested stock options
 
 
 
 
 
 
 
 
 
 
3,126 
 
 
 
 
3,128 
Exercise of vested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
1,696,318 
 
 
 
 
 
 
Vesting of early exercised stock options
 
 
 
 
 
 
 
 
 
 
 
201 
 
 
 
 
201 
Exercises of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
70,874 
 
 
 
 
 
 
Repurchase of shares in tender offer
 
 
 
 
 
 
 
 
(315)
 
(2)
 
 
(17,076)
 
 
(17,393)
Repurchase of shares in tender offer (in shares)
 
 
 
 
 
 
 
 
(365,916)
 
(1,869,156)
 
 
 
 
 
 
Deemed dividend in relation to tender offer
 
 
 
 
 
 
 
 
 
 
 
 
 
(3,392)
 
 
(3,392)
Repurchase of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
(20,084)
 
 
 
 
 
 
Issuance of Series T convertible preferred Stock in acquisition
 
 
 
 
 
 
 
 
3,087 
 
 
 
 
 
 
 
3,087 
Issuance of Series T convertible preferred Stock in acquisition (in shares)
 
 
 
 
 
 
 
 
897,618 
 
 
 
 
 
 
 
 
Stock-based compensation
 
 
 
 
 
 
 
 
 
 
 
9,856 
 
 
 
 
9,856 
Ending balance at Dec. 31, 2015
 
 
 
 
 
 
 
 
239,911 
 
17 
22,103 
 
(145,406)
 
 
116,625 
Ending balance (in shares) at Dec. 31, 2015
 
 
 
 
 
 
 
 
54,508,441 
 
17,324,003 
 
 
 
 
 
 
Increase (Decrease) in Stockholders' Equity
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Net loss
 
 
 
 
 
 
 
 
 
 
 
 
 
(41,324)
 
 
(41,324)
Issuance of stock
12 
160,414 
 
160,426 
65,279 
 
65,281 
 
 
 
 
 
 
 
 
 
Issuance of stock (in shares)
11,500,000 
 
 
 
1,691,222 
 
 
 
 
 
 
 
 
 
 
 
 
Costs related to public offerings
 
 
 
(4,900)
 
 
 
(800)
 
 
 
(5,730)
 
 
 
 
(5,730)
Conversion of convertible preferred stock to common stock in connection with initial public offering
 
 
 
 
 
 
 
 
(239,911)
 
54 
239,857 
 
 
 
 
 
Conversion of convertible preferred stock to common stock in connection with initial public offering (in shares)
 
 
 
 
 
 
 
 
(54,508,441)
 
54,508,441 
 
 
 
 
 
 
Exercise of vested stock options
 
 
 
 
 
 
 
 
 
 
8,390 
 
 
 
 
8,392 
Exercise of vested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
2,168,287 
 
 
 
 
 
 
Vesting of early exercised stock options
 
 
 
 
 
 
 
 
 
 
 
636 
 
 
 
 
636 
Vesting of restricted stock units (in shares)
 
 
 
 
 
 
 
 
 
19,178 
68,345 
 
 
 
 
 
 
Value of equity awards withheld for tax liability
 
 
 
 
 
 
 
 
 
 
 
(1,037)
 
 
 
 
(1,037)
Value of equity awards withheld for tax liability (in shares)
 
 
 
 
 
 
 
 
 
(1,578)
(27,036)
 
 
 
 
 
 
Exercises of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
126,365 
 
 
 
 
 
 
Conversion of shares of Class B common stock into shares of Class A common stock
 
 
 
 
 
 
 
 
 
37 
(37)
 
 
 
 
 
 
Conversion of shares of Class B common stock into shares of Class A common stock (in shares)
 
 
 
 
 
 
 
 
 
36,787,588 
(36,787,588)
 
 
 
 
 
 
Repurchase of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
(1,625)
 
 
 
 
 
 
Stock-based compensation
 
 
 
 
 
 
 
 
 
 
 
26,178 
 
 
 
 
26,178 
Escrow shares returned to the issuer (in shares)
 
 
 
 
 
 
 
 
 
 
(127,054)
 
 
 
 
 
 
Ending balance at Dec. 31, 2016
 
 
 
 
 
 
 
 
 
51 
36 
516,090 
 
(186,730)
 
 
329,447 
Ending balance (in shares) at Dec. 31, 2016
 
 
 
 
 
 
 
 
 
49,996,410 
37,252,138 
 
 
 
 
 
 
Increase (Decrease) in Stockholders' Equity
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Net loss
 
 
 
 
 
 
 
 
 
 
 
 
 
(63,708)
 
 
(63,708)
Exercise of vested stock options
 
 
 
 
 
 
 
 
 
 
25,591 
 
 
 
 
25,597 
Exercise of vested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
5,186,539 
 
 
 
 
 
 
Vesting of early exercised stock options
 
 
 
 
 
 
 
 
 
 
 
378 
 
 
 
 
378 
Vesting of restricted stock units (in shares)
 
 
 
 
 
 
 
 
 
360,116 
351,255 
 
 
 
 
 
 
Value of equity awards withheld for tax liability
 
 
 
 
 
 
 
 
 
 
 
(678)
 
 
 
 
(678)
Value of equity awards withheld for tax liability (in shares)
 
 
 
 
 
 
 
 
 
 
(22,538)
 
 
 
 
 
 
Exercises of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
22,510 
 
 
 
 
 
 
Conversion of shares of Class B common stock into shares of Class A common stock
 
 
 
 
 
 
 
 
 
18 
(18)
 
 
 
 
 
 
Conversion of shares of Class B common stock into shares of Class A common stock (in shares)
 
 
 
 
 
 
 
 
 
18,710,499 
(18,710,499)
 
 
 
 
 
 
Shares issued under ESPP
 
 
 
 
 
 
 
 
 
 
11,917 
 
 
 
 
11,918 
Shares issued under ESPP (in shares)
 
 
 
 
 
 
 
 
 
794,142 
 
 
 
 
 
 
 
Donated common stock
 
 
 
 
 
 
 
 
 
 
 
1,172 
 
 
 
 
1,172 
Donated common stock (in shares)
 
 
 
 
 
 
 
 
 
45,383 
 
 
 
 
 
 
 
Repurchase of unvested stock options
 
 
 
 
 
 
 
 
 
 
 
(100)
 
 
 
 
(100)
Repurchase of unvested stock options (in shares)
 
 
 
 
 
 
 
 
 
 
(16,159)
 
 
 
 
 
 
Unrealized loss on marketable securities
 
 
 
 
 
 
 
 
 
 
 
 
(598)
 
 
 
(598)
Foreign currency translation
 
 
 
 
 
 
 
 
 
 
 
 
2,623 
 
 
 
2,623 
Stock-based compensation
 
 
 
 
 
 
 
 
 
 
 
53,795 
 
 
 
 
53,795 
Ending balance at Dec. 31, 2017
 
 
 
 
 
 
 
 
 
$ 70 
$ 24 
$ 608,165 
$ 2,025 
$ (250,438)
 
 
$ 359,846 
Ending balance (in shares) at Dec. 31, 2017
 
 
 
 
 
 
 
 
 
69,906,550 
24,063,246 
 
 
 
 
 
 
Consolidated Statements of Stockholders' Equity (Parenthetical) (Preferred Stock, Series E Preferred Stock, USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2015
Preferred Stock |
Series E Preferred Stock
 
Consolidated Statements of Stockholders' Equity
 
Costs related to issuance of stock
$ 4.6 
Consolidated Statements of Cash Flows (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
 
 
 
Net loss
$ (63,708)
$ (41,324)
$ (35,504)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
 
 
 
Depreciation and amortization
18,764 
8,315 
4,226 
Amortization of bond premium
262 
 
 
Stock-based compensation
49,619 
24,225 
8,877 
Value of donated common stock
1,172 
 
 
Provision for doubtful accounts
580 
1,145 
705 
Tax benefit related to acquisition
 
 
(108)
Write-off of internal-use software
561 
711 
113 
(Gain) loss on lease termination
(295)
94 
 
Changes in operating assets and liabilities:
 
 
 
Accounts receivable
(15,280)
(8,254)
(10,506)
Prepaid expenses and other current assets
2,214 
(13,755)
(2,128)
Other long-term assets
(1,989)
(135)
(162)
Accounts payable
5,433 
1,714 
658 
Accrued expenses and other current liabilities
(3,312)
24,182 
13,202 
Deferred revenue
3,560 
4,076 
1,974 
Long-term liabilities
(841)
9,097 
(109)
Net cash provided by (used in) operating activities
(3,260)
10,091 
(18,762)
CASH FLOWS FROM INVESTING ACTIVITIES:
 
 
 
(Increase) decrease in restricted cash
3,118 
(7,439)
 
Purchases of marketable securities
(293,186)
 
 
Maturities of marketable securities
115,877 
 
 
Capitalized software development costs
(17,280)
(11,527)
(8,409)
Purchases of property and equipment
(9,248)
(14,174)
(1,715)
Purchases of intangible assets
(290)
(785)
(494)
Acquisition, net of cash acquired
(22,621)
(8,500)
(1,761)
Net cash used in investing activities
(223,630)
(42,425)
(12,379)
CASH FLOWS FROM FINANCING ACTIVITIES:
 
 
 
Proceeds from Initial Public Offering, net of underwriting discounts
 
160,426 
 
Proceeds from Follow-On Public Offering, net of underwriting discounts
 
65,281 
 
Payments of costs related to public offerings
(430)
(4,606)
(694)
Net proceeds from issuance of convertible preferred stock
 
 
125,448 
Proceeds from exercises of vested options
25,597 
8,392 
3,128 
Proceeds from exercises of nonvested options
130 
710 
277 
Proceeds from shares issued in ESPP
11,918 
 
 
Value of equity awards withheld for tax liabilities
(678)
(1,037)
 
Repurchases of common and preferred stock
(100)
(2)
(20,810)
Net cash provided by financing activities
36,437 
229,164 
107,349 
Effect of exchange rate changes on cash and cash equivalents
74 
 
 
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS
(190,379)
196,830 
76,208 
CASH AND CASH EQUIVALENTS-Beginning of year
305,665 
108,835 
32,627 
CASH AND CASH EQUIVALENTS-End of year
115,286 
305,665 
108,835 
Cash paid for income taxes
605 
225 
46 
NON-CASH INVESTING AND FINANCING ACTIVITIES:
 
 
 
Purchases of property, equipment and intangible assets, accrued but not paid
235 
4,201 
97 
Stock-based compensation capitalized in software development costs
4,176 
1,953 
979 
Vesting of early exercised options
378 
636 
201 
Business combination measurement period adjustments
(149)
 
 
Series T convertible preferred stock issued as part of purchase price in the Authy acquisition
 
 
3,087 
Costs related to public offerings, accrued but not paid
 
$ 430 
$ 1,265 
Organization and Description of Business
Organization and Description of Business

1. Organization and Description of Business

        Twilio Inc. (the "Company") was incorporated in the state of Delaware on March 13, 2008. The Company is the leader in the Cloud Communications Platform category and enables developers to build, scale and operate real-time communications within their software applications via simple-to-use Application Programming Interfaces, or API. The power, flexibility, and reliability offered by the Company's software building blocks empower entities of virtually every shape and size to build world-class engagement into their customer experience.

        The Company's headquarters are located in San Francisco, California and the Company has subsidiaries in the United Kingdom, Estonia, Ireland, Colombia, Germany, Hong Kong, Singapore, Bermuda, Spain, Sweden and Australia.

Initial Public Offering

        In June 2016, the Company completed an initial public offering ("IPO") in which the Company sold 11,500,000 shares of its newly authorized Class A common stock, which included 1,500,000 shares sold pursuant to the exercise by the underwriters of an option to purchase additional shares, at the public offering price of $15.00 per share. The Company received net proceeds of $155.5 million, after deducting underwriting discounts and offering expenses paid by the Company, from the sale of its shares in the IPO. Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified as shares of Class B common stock and all shares of convertible preferred stock then outstanding were converted into 54,508,441 shares of common stock on a one-to-one basis, and then reclassified as shares of Class B common stock. See Note 11 for further discussion of Class A and B common stock.

Follow-on Public Offering

        In October 2016, the Company completed a follow-on public offering ("FPO") in which the Company sold 1,691,222 shares of its Class A common stock, which included 1,050,000 shares sold pursuant to the exercise by the underwriters of an option to purchase additional shares, at a public offering price of $40.00 per share. In addition, another 6,358,778 shares of the Company's Class A common stock were sold by the selling stockholders of the Company, which included 906,364 shares sold pursuant to the exercise of employee stock options by certain selling stockholders. The Company received aggregate proceeds of $64.4 million, after deducting underwriting discounts and offering expenses paid and payable by the Company. The Company did not receive any of the net proceeds from the sales of shares by the selling stockholders.

Summary of Significant Accounting Policies
Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

 

 

 

           

(a)          

Basis of Presentation

        The Company's consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP").

 

 

 

           

(b)          

Principles of Consolidation

        The consolidated financial statements include the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated.

 

 

 

           

(c)          

Use of Estimates

        The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates are used for, but not limited to, revenue allowances and returns; valuation of the Company's stock and stock-based awards; recoverability of long-lived and intangible assets; capitalization and useful life of the Company's capitalized internal-use software development costs; fair value of acquired intangible assets and goodwill; accruals and contingencies. Estimates are based on historical experience and on various assumptions that the Company believes are reasonable under current circumstances. However, future events are subject to change and best estimates and judgments may require further adjustments; therefore, actual results could differ materially from those estimates. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation.

 

 

 

           

(d)          

Concentration of Credit Risk

        Financial instruments that potentially expose the Company to a concentration of credit risk consist primarily of cash, cash equivalents, marketable securities, restricted cash and accounts receivable. The Company maintains cash, cash equivalents, restricted cash and marketable securities with financial institutions that management believes are financially sound and have minimal credit risk exposure although the balances will exceed insured limits.

        The Company sells its services to a wide variety of customers. If the financial condition or results of operations of any significant customers deteriorate substantially, operating results could be adversely affected. To reduce credit risk, management performs ongoing credit evaluations of the financial condition of significant customers. The Company does not require collateral from its credit customers and maintains reserves for estimated credit losses on customer accounts when considered necessary. Actual credit losses may differ from the Company's estimates. During the year ended December 31, 2017, there was no customer organization that accounted for more than 10% of the Company's total revenue. During the year ended December 31, 2016, one customer organization represented approximately 14% of the Company's total revenue. During the year ended December 31, 2015, a different customer organization represented approximately 17% of the Company's total revenue.

        As of December 31, 2017, no customer organizations represented more than 10% of the Company's gross accounts receivable. As of December 31, 2016, one customer organization represented approximately 16% of the Company's gross accounts receivable.

 

 

 

           

(e)          

Revenue Recognition

        The Company derives its revenue primarily from usage-based fees earned from customers accessing the Company's enterprise cloud computing services invoiced or paid monthly. The Company provides services to its customers under pay-as-you-go contracts and term-based contracts ranging in duration from one month to 48 months. Customers that pay via credit card are either billed in advance or as they use service. Larger customers are billed in arrears via invoices for services used. Certain customers have contracts that provide for a minimum monthly commitment and some customers have contracts that provide for a commitment that may be of a quarterly, annual or other specific durations.

        The Company recognizes revenue from these transactions when all of the following criteria are satisfied:

 

 

 

           

•          

there is persuasive evidence of an arrangement; 

           

•          

the service has been or is being provided to the customer; 

           

•          

the amount of the fees to be paid by the customer is fixed or determinable; and 

           

•          

collectability of the fees is reasonably assured.

        Term-based contracts revenue is recognized on a straight-line basis over the contractual term of the arrangement beginning on the date that the service is made available to the customer, provided that all other revenue recognition criteria have been met. Usage-based fees are recognized as delivered.

        The Company's arrangements do not contain general rights of return. However, credits may be issued to customers on a case-by-case basis. The contracts do not provide customers with the right to take possession of the software supporting the applications. Amounts that have been invoiced are recorded in accounts receivable and in revenue or deferred revenue, depending on whether the revenue recognition criteria have been met.

        The reserve for sales credits was $1.8 million and $0.5 million as of December 31, 2017 and 2016, respectively, and is included in accounts receivable, net in the accompanying consolidated balance sheets. The reserve for sales credits is calculated based on historical trends and any specific risks identified in processing transactions. Changes in the reserve are recorded against revenue.

        The Company collects various taxes and fees as an agent in connection with the sale of its services and remits these amounts to the respective taxing authorities. These taxes and fees have been presented on a net basis in the consolidated statements of operations and are recorded as a component of accrued liabilities in the accompanying consolidated balance sheets until remitted to the respective taxing authority.

 

 

 

           

(f)          

Cost of Revenue

        Cost of revenue consists primarily of costs of communications services purchased from network service providers. Cost of revenue also includes fees to support the Company's cloud infrastructure, personnel costs, such as salaries and stock-based compensation for the customer care and support services employees, and non-personnel costs, such as amortization of capitalized internal-use software development costs.

 

 

 

           

(g)          

Research and Development Expenses

        Research and development expenses consist primarily of personnel costs, cloud infrastructure fees for staging and development, outsourced engineering services, amortization of capitalized internal-use software development costs and an allocation of general overhead expenses. The Company capitalizes the portion of its software development costs that meets the criteria for capitalization.

 

 

 

           

(h)          

Internal-Use Software Development Costs

        Certain costs of platform and other software applications developed for internal use are capitalized. The Company capitalizes qualifying internal-use software development costs that are incurred during the application development stage. Capitalization of costs begins when two criteria are met: (i) the preliminary project stage is completed and (ii) it is probable that the software will be completed and used for its intended function. Capitalization ceases when the software is substantially complete and ready for its intended use, including the completion of all significant testing. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality and expenses costs incurred for maintenance and minor upgrades and enhancements. Costs related to preliminary project activities and post-implementation operating activities are also expensed as incurred.

        Capitalized costs of platform and other software applications are included in property and equipment. These costs are amortized over the estimated useful life of the software on a straight-line basis over three years. Management evaluates the useful life of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. The amortization of costs related to the platform applications is included in cost of revenue, while the amortization of costs related to other software applications developed for internal use is included in research and development expenses.

 

 

 

           

(i)          

Advertising Costs

        Advertising costs are expensed as incurred and were $4.9 million, $3.5 million and $2.9 million in the years ended December 31, 2017, 2016 and 2015, respectively. Advertising costs are included in sales and marketing expenses in the accompanying consolidated statements of operations.

 

 

 

           

(j)          

Stock-Based Compensation

        All stock-based compensation to employees, including the purchase rights issued under the Company's 2016 Employee Stock Purchase Plan (the "ESPP"), is measured on the grant date based on the fair value of the awards on the date of grant. This cost is recognized as an expense following the ratable attribution method, over the requisite service period, for stock options, and the straight-line attribution method, over the offering period, for the purchase rights issued under the ESPP. The Company uses the Black-Scholes option pricing model to measure the fair value of its stock options and the purchase rights issued under the ESPP. The fair value of the restricted stock units is determined using the fair value of the Company's Class A common stock on the date of grant. Prior to adoption of ASU 2016-09, the stock-based compensation was recorded net of estimated forfeitures.

        In March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-09, "Compensation—Stock Compensation (Topic 718): Improvements to Employee Share -Based Payment Accounting." This new guidance was intended to simplify several areas of accounting for stock-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The Company early adopted this guidance in the quarter ended December 31, 2016. The new guidance allows entities to account for forfeitures as they occur. The Company elected to account for forfeitures as they occur and adopted this provision on a modified retrospective basis. The $0.1 million of cumulative prior years' impact as well as the impact on the first three quarters of 2016 of $75,000 was recognized as an increase to stock-based compensation during the quarter ended December 31, 2016, as the impact on prior periods was insignificant. Adoption of all other changes in the new guidance did not have a significant impact on the Company's consolidated financial statements.

        Prior to the IPO, the fair value of the Company's common stock was determined by the estimated fair value of the Company's common stock at the time of grant. After the IPO, the Company uses the market closing price of its Class A common stock as reported on the New York Stock Exchange for the fair value.

        Compensation expense for stock options granted to nonemployees is calculated using the Black-Scholes option pricing model and is recognized in expense over the service period. Compensation expense for nonemployee stock options subject to vesting is revalued at each reporting date until the stock options are vested.

        The Black-Scholes option pricing model requires the use of complex assumptions, which determine the fair value of stock-based awards. These assumptions include:

 

 

 

           

•          

Fair value of the common stock.  Prior to the Company's IPO, the board of directors considered numerous objective and subjective factors to determine the fair value of the Company's common stock at each meeting at which awards are approved. The factors included, but were not limited to: (i) contemporaneous valuations of the Company's common stock by an unrelated third party; (ii) the prices at which the Company sold shares of its convertible preferred stock to outside investors in arms-length transactions; (iii) the rights, preferences and privileges of the Company's convertible preferred stock relative to those of its common stock; (iv) the Company's results of operations, financial position and capital resources; (v) current business conditions and projections; (vi) the lack of marketability of the Company's common stock; (vii) the hiring of key personnel and the experience of management; (viii) the introduction of new products; (ix) the risk inherent in the development and expansion of the Company's products; (x) the Company's stage of development and material risks related to its business; (xi) the fact that the option grants involve illiquid securities in a private company; and (xii) the likelihood of achieving a liquidity event, such as an initial public offering or sale of the Company, in light of prevailing market conditions; 

           

•          

Expected term.  The expected term represents the period that the stock-based awards are expected to be outstanding. The Company uses the simplified calculation of expected term, as the Company does not have sufficient historical data to use any other method to estimate expected term; 

           

•          

Expected volatility.  The expected volatility is derived from an average of the historical volatilities of the common stock of several entities with characteristics similar to those of the Company, such as the size and operational and economic similarities to the Company's principal business operations; 

           

•          

Risk -free interest rate.  The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero coupon U.S. Treasury notes with maturities approximately equal the expected term of the stock-based awards; and 

           

•          

Expected dividend.  The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock.

        If any of the assumptions used in the Black-Scholes model changes, stock-based compensation for future options may differ materially compared to that associated with previous grants.

 

 

 

           

(k)          

Income Taxes

        The Company accounts for income taxes in accordance with authoritative guidance which requires the use of the asset and liability approach. Deferred tax assets and liabilities are recognized for future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss and tax credit carry-forwards. Deferred tax amounts are determined by using the enacted tax rates expected to be in effect when the temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance reduces the deferred tax assets to the amount that is more likely than not to be realized.

        The Company recognizes the effect of uncertain income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.

        The Company records interest and penalties related to uncertain tax positions in the provision for income taxes in the consolidated statements of operations.

 

 

 

           

(l)          

Foreign Currency Translation

        The functional currency of the Company's foreign subsidiaries is generally the U.S. dollar. Accordingly, the subsidiaries remeasure monetary assets and liabilities at period-end exchange rates, while non-monetary items are remeasured at historical rates. Revenue and expense accounts are remeasured at the average exchange rate in effect during the year. Remeasurement adjustments are recognized in the consolidated statements of operations as other income or expense in the year of occurrence. Foreign currency transaction gains and losses were insignificant for all periods presented.

        For those entities where the functional currency is a foreign currency, adjustments resulting from translating the financial statements into U.S. dollars are recorded as a component of accumulated other comprehensive income (loss) in stockholders' equity. Monetary assets and liabilities denominated in a foreign currency are translated into US dollars at the exchange rate on the balance sheet date. Revenue and expenses are translated at the weighted average exchange rates during the period. Equity transactions are translated using historical exchange rates. Foreign currency transaction gains and losses are included in other income (expense), net in the consolidated statements of operations.

 

 

 

           

(m)          

Comprehensive Income (Loss)

        Comprehensive income (loss) refers to net income (loss) and other revenue, expenses, gains and losses that, under generally accepted accounting principles, are recorded as an element of stockholders' equity but are excluded from the calculation of net income (loss).

        For the years ended December 31, 2016 and 2015, the Company's operations did not give rise to any material items includable in comprehensive income (loss), which were not already in net income (loss). Accordingly, for those periods, the Company's comprehensive income (loss) is the same as its net income (loss).

 

 

 

           

(n)          

Net Loss Per Share Attributable to Common Stockholders

        The Company calculates its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. All series of convertible preferred stock are considered to be participating securities as the holders of the preferred stock are entitled to receive a non-cumulative dividend on a pro rata pari passu basis in the event that a dividend is declared or paid on common stock. Shares of common stock issued upon early exercise of stock options that are subject to repurchase are also considered to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is declared or paid on common stock. Under the two-class method, in periods when the Company has net income, net income attributable to common stockholders is determined by allocating undistributed earnings, calculated as net income less current period convertible preferred stock non-cumulative dividends, between common stock and the convertible preferred stock. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. The Company's basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. The dilutive effect of these potential common shares is reflected in diluted earnings per share by application of the treasury stock method. For purposes of this calculation, convertible preferred stock, options to purchase common stock, unvested restricted stock units, common stock issued subject to future vesting, any shares of stock committed under the ESPP, any shares of stock held in escrow and any shares of stock reserved for future donations are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.

        Since the Company's IPO in 2016, Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder on a one-for-one basis, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Shares of Class A common stock are not convertible.

 

 

 

           

(o)          

Cash and Cash Equivalents

        The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of funds deposited into money market funds. All credit and debit card transactions that process as of the last day of each month and settle within the first few days of the subsequent month are also classified as cash and cash equivalents as of the end of the month in which they were processed.

 

 

 

           

(p)          

Restricted Cash

        Restricted cash consists of cash deposited into a savings account with a financial institution as collateral for the Company's obligations under its facility leases of premises located in San Francisco, California. The facility lease for the Company's old office space expired in January 2017 and the facility lease for the Company's new office space expires in October 2024. The restricted cash balances as of December 31, 2017 and December 31, 2016 were $5.5 million and $8.6 million, respectively.

 

 

 

           

(q)          

Accounts Receivable and Allowance for Doubtful Accounts

        Accounts receivable are recorded net of the allowance for doubtful accounts and the reserve for sales credits. The allowance for doubtful accounts is estimated based on the Company's assessment of its ability to collect on customer accounts receivable. The Company regularly reviews the allowance by considering certain factors such as historical experience, credit quality, age of accounts receivable balances and other known conditions that may affect a customer's ability to pay. In cases where the Company is aware of circumstances that may impair a specific customer's ability to meet their financial obligations, a specific allowance is recorded against amounts due from the customer which reduces the net recognized receivable to the amount the Company reasonably believe will be collected. The Company writes-off accounts receivable against the allowance when a determination is made that the balance is uncollectible and collection of the receivable is no longer being actively pursued. The allowance for doubtful accounts was $1.0 million and $1.1 million as of December 31, 2017 and 2016, respectively.

 

 

 

           

(r)          

Costs Related to the Public Offerings

        Costs related to the public offerings, which consist of direct incremental legal, printing and accounting fees, are deferred until the offering is completed. Upon completion of the offering, these costs are offset against the offering proceeds within the consolidated statements of stockholders' equity. As of December 31, 2016, the Company recorded in its consolidated statement of stockholders' equity $5.7 million in total offering costs, of which $4.9 million and $0.8 million related to the IPO and the FPO, respectively.

 

 

 

           

(s)          

Property and Equipment

        Property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful life of the related asset. Maintenance and repairs are charged to expenses as incurred.

        The useful lives of property and equipment are as follows:

                                                                                                                                                                                    

Capitalized software development costs

 

3 years

Office equipment

 

3 years

Furniture and fixtures

 

5 years

Software

 

3 years

Leasehold improvements

 

5 years or remaining lease term

 

 

 

 

           

(t)          

Intangible Assets

        Intangible assets recorded by the Company are costs directly associated with securing legal registration of patents and trademarks, acquiring domain names and the fair value of identifiable intangible assets acquired in business combinations.

        Intangible assets with determinable economic lives are carried at cost, less accumulated amortization. Amortization is computed over the estimated useful life of each asset on a straight-line basis. The Company determines the useful lives of identifiable intangible assets after considering the specific facts and circumstances related to each intangible asset. Factors the Company considers when determining useful lives include the contractual term of any agreement related to the asset, the historical performance of the asset, the Company's long-term strategy for using the asset, any laws or other local regulations which could impact the useful life of the asset and other economic factors, including competition and specific market conditions. Intangible assets without determinable economic lives are carried at cost, not amortized and reviewed for impairment at least annually.

        The useful lives of the intangible assets are as follows:

                                                                                                                                                                                    

Developed technology

 

3 - 4 years

Customer relationships

 

5 - 8 years

Supplier relationships

 

5 years

Trade names

 

2 years

Patents

 

20 years

Trademarks

 

Indefinite

Domain names

 

Indefinite

 

 

 

 

           

(u)          

Goodwill

        Goodwill represents excess of the aggregate purchase price over the fair value of net identifiable assets acquired in a business combination. Goodwill is not amortized and is tested for impairment at least annually or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that it operates as one reporting unit and has selected November 30 as the date to perform its annual impairment test. In the valuation of goodwill, management must make assumptions regarding estimated future cash flows to be derived from the Company's business. If these estimates or their related assumptions change in the future, the Company may be required to record impairment for these assets. Management may first evaluate qualitative factors to assess if it is more likely than not that the fair value of a reporting unit is less than its carrying amount and to determine if a two-step impairment test is necessary. Management may choose to proceed directly to the two-step evaluation, bypassing the initial qualitative assessment. The first step of the impairment test involves comparing the fair value of the reporting unit to its net book value, including goodwill. If the net book value exceeds its fair value, then the Company would perform the second step of the goodwill impairment test to determine the amount of the impairment loss. The impairment loss would be calculated by comparing the implied fair value of the goodwill to its net book value. In calculating the implied fair value of goodwill, the fair value of the entity would be allocated to all of the other assets and liabilities based on their fair values. The excess of the fair value of the entity over the amount assigned to other assets and liabilities is the implied fair value of goodwill. An impairment loss would be recognized when the carrying amount of goodwill exceeds its implied fair value. No goodwill impairment charges have been recorded for any period presented.

 

 

 

           

(v)          

Impairment of Long-Lived Assets

        The Company evaluates long-lived assets, including property and equipment and intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets held and used is measured by a comparison of the carrying amount of an asset or an asset group to estimated undiscounted future net cash flows expected to be generated by the asset or asset group. If such evaluation indicates that the carrying amount of the asset or the asset group is not recoverable, any impairment loss would be equal to the amount the carrying value exceeds the fair value. There was no impairment during the years ended December 31, 2017, 2016 and 2015. The value of the internally-developed software written-off due to abandonment was $0.6 million, $0.7 million and $0.1 million in the years ended December 31, 2017, 2016 and 2015, respectively.

 

 

 

           

(w)          

Deferred Revenue

        Deferred revenue consists of cash deposits from customers to be applied against future usage and customer billings in advance of revenues being recognized from the Company's contracts. Deferred revenue is generally expected to be recognized during the succeeding 12-month period and is thus recorded as a current liability. Deferred revenue is refunded in cash upon termination of customer accounts.

 

 

 

           

(x)          

Business Combinations

        The Company recognizes identifiable assets acquired and liabilities assumed at their acquisition date fair values. Goodwill is measured as the excess of the consideration transferred over the fair value of assets acquired and liabilities assumed on the acquisition date. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to accurately value assets acquired and liabilities assumed, these estimates are inherently uncertain and subject to refinement. The authoritative guidance allows a measurement period of up to one year from the date of acquisition to make adjustments to the preliminary allocation of the purchase price. As a result, during the measurement period the Company may record adjustments to the fair values of assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that it identifies adjustments to the preliminary purchase price allocation. Upon conclusion of the measurement period or final determination of the values of the assets acquired and liabilities assumed, whichever comes first, any subsequent adjustments will be recorded to the consolidated statement of operations.

 

 

 

           

(y)          

Segment Information

        The Company's Chief Executive Officer is the chief operating decision maker, who reviews the Company's financial information presented on a consolidated basis for purposes of allocating resources and evaluating the Company's financial performance. Accordingly, the Company has determined that it operates in a single reporting segment.

 

 

 

           

(z)          

Fair Value of Financial Instruments

        The Company applies fair value accounting for all financial instruments on a recurring basis. The Company's financial instruments, which include cash, cash equivalents, accounts receivable and accounts payable are recorded at their carrying amounts, which approximate their fair values due to their short-term nature. Restricted cash is long-term in nature and consists of cash in a savings account, hence its carrying amount approximates its fair value. Marketable securities consist of U.S. treasury securities and high credit quality corporate debt securities. All marketable securities are considered to be available-for-sale and recorded at their estimated fair values. Unrealized gains and losses for available-for-sale securities are recorded in other comprehensive income (loss). In valuing these items, the Company uses inputs and assumptions that market participants would use to determine their fair value, utilizing valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs.

        Impairments are considered to be other than temporary if they are related to deterioration in credit risk or if it is likely that the security will be sold before the recovery of its cost basis. Realized gains and losses and declines in value deemed to be other than temporary are determined based on the specific identification method and are reported in other income (expense), net.

        The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows:

 

 

 

           

•          

Level 1 Inputs:  Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. 

           

•          

Level 2 Inputs:  Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. 

           

•          

Level 3 Inputs:  Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date.

        A financial instrument's categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

 

 

 

           

(aa)          

Recent Accounting Pronouncements Not Yet Adopted

        In May 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Updates ("ASU") 2017-09, "Compensation-Stock Compensation (Topic 718), Scope of Modification Accounting", which clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The guidance is effective prospectively for interim and annual periods beginning after December 15, 2017 and early adoption is permitted. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have a material impact on the Company's financial position, results of operations or cash flows.

        In January 2017, the FASB issued ASU 2017-04, "Simplifying the Test for Goodwill Impairment", which removes the second step of the goodwill impairment test that requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This guidance is effective prospectively for interim and annual reporting periods beginning after December 15, 2019. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have a material impact on the Company's financial position, results of operations or cash flows.

        In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805) Clarifying the Definition of a Business", which amends the guidance of FASB Accounting Standards Codification Topic 805, "Business Combinations", adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted under certain circumstances. The Company will adopt this guidance upon its effective date and implement it next time there is a potential business combination.

        In November 2016, the FASB issued ASU 2016-18, "Restricted Cash", which requires a statement of cash flows to explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash and restricted cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted. The Company will adopt this guidance upon its effective date and its impact will be a function of the amounts of restricted cash the Company has at that time and the movements therein.

        In October 2016, the FASB issued ASU 2016-16, "Intra-Entity Transfers Other Than Inventory", which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have any material impact on the Company's financial position, results of operations or cash flows.

        In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments", which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

        In February 2016, the FASB issued ASU No. 2016-02, "Leases." The standard will affect all entities that lease assets and will require lessees to recognize a lease liability and a right-of-use asset for all leases (except for short-term leases that have a duration of less than one year) as of the date on which the lessor makes the underlying asset available to the lessee. For lessors, accounting for leases is substantially the same as in prior periods. For public companies, the new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. For leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, lessees and lessors must apply a modified retrospective transition approach. While the Company expects the adoption of this standard to result in an increase to the reported assets and liabilities, the Company has not yet determined the full impact that the adoption of this standard will have on its consolidated financial statements and related disclosures.

        In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers". This new guidance will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14 which deferred, by one year, the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net)" clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, "Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing", clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). In May 2016, the FASB issued ASU 2016-12 "Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients", which amends the guidance on transition, collectability, noncash consideration and the presentation of sales and other similar taxes. ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all (or substantially all) of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard's contract criteria. In September 2017, the FASB issued ASU 2017-13, "Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606), Leases (Topic 840), and Leases (Topic 842)". These amendments provide additional clarification and implementation guidance on the previously issued ASUs. These amendments do not change the core principles of the guidance stated in ASU 2014-09, instead they are intended to clarify and improve operability of certain topics included within the revenue standard. In November 2017, the FASB issued ASU 2017-14, which includes amendments to certain SEC paragraphs within the FASB Accounting Standards Codification (Codification). ASU 2017-14 amends the Codification to incorporate SEC Staff Accounting Bulletin (SAB) No. 116 and SEC Interpretive Release on Vaccines for Federal Government Stockpiles (SEC Release No. 33-10403) that bring existing SEC staff guidance into conformity with the FASB's adoption of and amendments to ASC Topic 606, Revenue from Contracts with Customers. The effective date and transition requirements for ASU 2016-08, ASU 2016-10, ASU 2016-12, ASU 2017-13 and ASU 2017-14 are the same as the effective date and transition requirements for ASU 2014-09. The Company has evaluated the potential changes from the adoption of the new standard on its financial statements and disclosures, and is in the process of implementing appropriate changes to its business processes, systems and controls to support revenue recognition and disclosures under the new standard. Based on this evaluation, the Company will adopt the requirements of the new standard in the first quarter of 2018, using the modified retrospective transition method with a cumulative catch adjustment to retained earnings as of January 1, 2018. Under the new standard, based on the Company's preliminary assessment, the Company does not believe there will be material changes to its revenue recognition and the expectation is that the majority of the Company's revenue will continue to be recognized according to the usage by its customers, in the period in which that usage occurs.

        The Company is also assessing the impact of adoption of the new standard on its accounting for sales commissions. The Company's current accounting policy requires capitalization and amortization of the deferred commissions. Under the new standard, the amounts capitalized will be recognized as amortization over the expected customer life. The Company's preliminary assessment of its analyses of the amortizable life of the deferred commissions under the new guidance at three years. Further review of certain commission plans is yet to be completed to finalize the impact on the consolidated statements of financial position, results of operations and cash flows.

        There will not be any significant tax impact to the Company's consolidated statements of operations and consolidated balance sheet relating to the adoption of the new standard as there will be a full valuation allowance due to the Company's history of continued losses.

Fair Value Measurements
Fair Value Measurements

3. Fair Value Measurements

        The following tables provide the assets measured at fair value on a recurring basis as of December 31, 2017 and 2016 (in thousands):

                                                                                                                                                                                    

 

 

 

 

 

 

Fair Value Hierarchy as of
December 31, 2017

 

 

 

 

 

Amortized
Cost or
Carrying
Value

 

 

 

 

 

 

 

Net
Unrealized
Losses

 

Aggregate
Fair Value

 

 

 

Level 1

 

Level 2

 

Level 3

 

Financial Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Money market funds

 

$

95,432

 

$

 

$

95,432

 

$

 

$

 

$

95,432

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total included in cash and cash equivalents

 

 

95,432

 

 

 

 

95,432

 

 

 

 

 

 

95,432

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Marketable securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. Treasury securities

 

 

59,962

 

 

(216

)

 

59,746

 

 

 

 

 

 

59,746

 

Corporate debt securities

 

 

116,223

 

 

(382

)

 

 

 

115,841

 

 

 

 

115,841

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total marketable securities

 

 

176,185

 

 

(598

)

 

59,746

 

 

115,841

 

 

 

 

175,587

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total financial assets

 

$

271,617

 

$

(598

)

$

155,178

 

$

115,841

 

$

 

$

271,019

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        There were no marketable securities as of December 31, 2016.

                                                                                                                                                                                    

 

 

 

 

As of December 31, 2016

 

 

 

Total
Carrying
Value

 

 

 

Level I

 

Level 2

 

Level 3

 

Total

 

Financial Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Money market funds (included in cash and cash equivalents)

 

$

274,135

 

$

274,135

 

$

 

$

 

$

274,135

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total financial assets

 

$

274,135

 

$

274,135

 

$

 

$

 

$

274,135

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        As the Company views these securities as available to support current operations, it has classified all available-for-sale securities as short term. The following table summarizes the contractual maturities of marketable securities as of December 31, 2017 (in thousands):

                                                                                                                                                                                    

 

 

Amortized
Cost

 

Aggregate
Fair Value

 

Financial Assets:

 

 

 

 

 

 

 

Less than one year

 

$

108,584

 

$

108,360

 

One to two years

 

 

67,601

 

 

67,227

 

​  

​  

​  

​  

Total

 

$

176,185

 

$

175,587

 

​  

​  

​  

​  

​  

​  

​  

​  

        For fixed income securities that had unrealized losses as of December 31, 2017, the Company has determined that no other-than-temporary impairment existed. As of December 31, 2017, all securities in an unrealized loss position have been in an unrealized loss position for less than one year. Interest earned on marketable securities in the year ended December 31, 2017 was $2.6 million and is recorded as other income (expense), net, in the accompanying consolidated statement of operations.

Property and Equipment
Property and Equipment

4. Property and Equipment

        Property and equipment consisted of the following (in thousands):

                                                                                                                                                                                    

 

 

As of December 31,

 

 

 

2017

 

2016

 

Capitalized internal-use software development costs

 

$

49,177

 

$

28,661

 

Leasehold improvements

 

 

14,246

 

 

14,063

 

Office equipment

 

 

9,652

 

 

5,729

 

Furniture and fixtures

 

 

1,976

 

 

1,576

 

Software

 

 

1,675

 

 

968

 

​  

​  

​  

​  

Total property and equipment

 

 

76,726

 

 

50,997

 

Less: accumulated depreciation and amortization

 

 

(26,185

)

 

(13,445

)

​  

​  

​  

​  

Total property and equipment, net

 

$

50,541

 

$

37,552

 

​  

​  

​  

​  

​  

​  

​  

​  

        Depreciation and amortization expense was $13.1 million, $7.4 million and $3.7 million for the years ended December 31, 2017, 2016 and 2015, respectively.

        The Company capitalized $21.5 million, $13.5 million and $9.4 million in internal-use software development costs in the years ended December 31, 2017, 2016 and 2015, respectively, of which $4.2 million, $2.0 million and $1.0 million, respectively, was stock-based compensation expense. Amortization of capitalized software development costs was $8.4 million, $5.5 million and $2.8 million in the years ended December 31, 2017, 2016 and 2015, respectively. The amortization expense was allocated as follows (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Cost of revenue

 

$

4,788

 

$

3,304

 

$

1,793

 

Research and development

 

 

3,619

 

 

2,182

 

 

1,045

 

​  

​  

​  

​  

​  

​  

Total

 

$

8,407

 

$

5,486

 

$

2,838

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Business Combinations
Business Combinations

5. Business Combinations

Beepsend, AB

        In February 2017, the Company completed its acquisition of Beepsend AB, a messaging provider based in Sweden, specializing in messaging and SMS solutions, for a total purchase price of $23.0 million, paid in cash, of which $5.0 million was held in escrow. The escrow will continue for 18 months after the transaction closing date and may be extended under certain circumstances.

        Additionally, the Company deposited $2.0 million into a separate escrow account that will be released to certain employees on the first and second anniversaries of the closing date, provided the underlying service conditions are met. This amount is recorded as prepaid compensation in the accompanying consolidated balance sheet and is amortized into expense as the services are rendered.

        The acquisition was accounted for as a business combination and, accordingly, the total purchase price was allocated to the preliminary net tangible and intangible assets and liabilities based on their preliminary fair values on the acquisition date. The prepaid compensation subject to service conditions is accounted for as a post-acquisition compensation expense and recorded as research and development expense in the accompanying consolidated statement of operations. During the measurement period in 2017, the Company recorded a net adjustments of $0.1 million to the preliminary purchase price allocation. As of December 31, 2017 the purchase price allocation is final.

        The acquired entity's results of operations have been included in the consolidated financial statements of the Company from the date of acquisition.

        The following table presents the purchase price allocation, as adjusted, recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Net tangible liabilities

 

$

(3,575

)

Goodwill(1)

 

 

12,837

 

Intangible assets(2)

 

 

13,700

 

​  

​  

Total purchase price

 

$

22,962

 

​  

​  

​  

​  


 

 

 

(1)          

Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer and supplier relationships as well as operational synergies. Goodwill is deductible for tax purposes.

(2)          

Identifiable finite-lived intangible assets were comprised of the following:

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

5,000

 

4

Customer relationships

 

 

6,100

 

7 - 8

Supplier relationships

 

 

2,600

 

5

​  

​  

Total intangible assets acquired

 

$

13,700

 

 

​  

​  

​  

​  

        The Company acquired a net deferred tax liability of $2.6 million in this business combination that is included in the long-term liabilities in the accompanying consolidated balance sheet.

        The estimated fair value of the intangible assets acquired was determined by the Company, and the Company considered or relied in part upon a valuation report of a third-party expert. The Company used income approaches to estimate the fair values of the identifiable intangible assets. Specifically, the developed technology asset class was valued using the-relief-from royalty method, while the customer relationships asset class was valued using a multi-period excess earnings method and the supplier relationships asset class was valued using an incremental cash flow method.

        The Company incurred costs related to this acquisition of $0.7 million, of which $0.3 million and $0.4 million were incurred during fiscal years 2017 and 2016, respectively. All acquisition related costs were expensed as incurred and have been recorded in general and administrative expenses in the accompanying consolidated statements of operations.

        Pro forma results of operations for this acquisition are not presented as the financial impact to the Company's consolidated financial statements is immaterial.

Kurento Open Source Project

        In November 2016, the Company acquired certain assets from Tikal Technologies S.L., a Spanish corporation, behind the Kurento Open Source Project. The acquired assets consisted of (a) proprietary WebRTC media processing technologies, (b) certain licenses, patents and trademarks and (c) certain employee relationships behind the WebRTC technology. The purchase price consisted of $8.5 million in cash, of which $1.5 million was placed into escrow to indemnify the Company against breaches of general representations, warranties, claims and tax compliance matters. The escrow is effective for 24 months and 10 days from the acquisition date and may be extended under certain circumstances.

        The acquisition was accounted for as a business combination and, accordingly, the total purchase price was allocated to the identifiable intangibles assets acquired based on their respective fair values on the acquisition date. The excess of the purchase price over the fair values of the identifiable assets acquired was recorded as goodwill. The Company considered or relied in part upon a valuation report of a third-party expert.

        The following table presents the final purchase price allocation recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Intangible assets(1)

 

$

8,100

 

Goodwill(2)

 

 

400

 

​  

​  

Total purchase price

 

$

8,500

 

​  

​  

​  

​  


 

 

 

(1)          

The intangible assets consist of developed technology with the estimated useful life of 3 years on the date of acquisition.

(2)          

The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology and the future development initiatives of the acquired workforce. The goodwill is deductible for tax purposes.

        The Company incurred cost related to this acquisition of $0.1 million that were expensed as incurred and have been recorded in general and administrative expenses in the accompanying consolidated statement of operations.

Authy, Inc.

        In February 2015, the Company completed its acquisition of Authy, Inc. ("Authy"), a Delaware corporation with operations in Bogota, Colombia and San Francisco, California. Authy had developed a two-factor authentication online security solution. The Company's purchase price of $6.1 million for all of the outstanding shares of capital stock of Authy consisted of $3.0 million in cash and $3.1 million representing the fair value of 389,733 shares of the Company's Series T convertible preferred stock, of which 180,000 shares were placed in escrow. The escrow was effective until the first anniversary of the closing date, and has continued beyond that date as a result of certain circumstances. As of December 31, 2017, the Company has not released any shares out of the escrow. Additionally, the Company issued 507,885 shares of its Series T convertible preferred stock, which converted into shares of Class B common stock immediately prior to the closing of the IPO, to a former shareholder of Authy that had a fair value of $4.0 million and were subject to a service condition over a period of three years, as amended. In August 2016, the unvested shares were reduced by 127,054 shares due to the non-fulfillment of certain conditions of the merger agreement. In December 2016, all remaining unvested shares vested.

        The acquisition was accounted for as a business combination and, accordingly, the total purchase price was allocated to the identifiable tangible and intangible assets acquired and the liabilities assumed based on their respective fair values on the acquisition date. The cost of shares subject to vesting and performance conditions was accounted for as a post-acquisition compensation expense and recorded as research and development expense in the accompanying consolidated statements of operations. The Company recorded $2.4 million and $0.6 million of stock-based compensation expense related to these shares in the years ended December 31, 2016 and 2015, respectively.

        Authy's results of operations have been included in the consolidated financial statements of the Company from the date of acquisition.

        This transaction was intended to qualify as a tax-free reorganization under Section 368(a) of the IRS Code.

        The fair value of the Series T convertible preferred stock was determined by the board of directors of the Company with input from a third-party valuation consultant.

        The following table presents the final purchase price allocation recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Net tangible assets

 

$

1,165

 

Goodwill(1)

 

 

3,165

 

Intangible assets(2)

 

 

1,760

 

​  

​  

Total purchase price

 

$

6,090

 

​  

​  

​  

​  

The Company acquired a net deferred tax liability of $0.1 million in this business combination.

 

 

 

 


 

 

 

(1)          

Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer base and the future development initiatives of the assembled workforce. Goodwill is not deductible for tax purposes.

(2)          

Identifiable finite-lived intangible assets were comprised of the following:

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

1,300

 

3

Customer relationships

 

 

400

 

5

Trade name

 

 

60

 

2

​  

​  

Total intangible assets acquired

 

$

1,760

 

 

​  

​  

​  

​  

        The estimated fair value of the intangible assets acquired was determined by the Company, and the Company considered or relied in part upon a valuation report of a third-party expert. The Company used an income approach to measure the fair values of the developed technology and trade names based on the relief-from-royalty method. The Company used an income approach to measure the fair value of the customer relationships based on the multi-period excess earnings method, whereby the fair value is estimated based upon the present value of cash flows that the applicable asset is expected to generate.

        The Company incurred costs related to this acquisition of $1.5 million, of which $1.2 million and $0.3 million were incurred during the years ended December 31, 2015 and 2014, respectively. All acquisition related costs were expensed as incurred and have been recorded in general and administrative expenses in the accompanying consolidated statements of operations.

        Pro forma results of operations for this acquisition are not presented as the financial impact to the Company's consolidated financial statements is immaterial.

Goodwill and Intangible Assets
Goodwill and Intangible Assets

6. Goodwill and Intangible Assets

Goodwill

        Goodwill balance as of December 31, 2017 and 2016 was as follows (in thousands):

                                                                                                                                                                                                

 

 

Total

 

Balance as of December 31, 2015

 

$

3,165

 

Goodwill recorded in connection with 2016 acquisition

 

 

400

 

​  

​  

Balance as of December 31, 2016

 

 

3,565

 

Goodwill recorded in connection with 2017 acquisition

 

 

12,688

 

Measurement period adjustment

 

 

149

 

Effect of exchange rate

 

 

1,449

 

​  

​  

Balance as of December 31, 2017

 

$

17,851

 

​  

​  

​  

​  

Intangible assets

        Intangible assets consisted of the following (in thousands):

                                                                                                                                                                                                

 

 

As of December 31, 2017

 

 

 

Gross

 

Accumulated
Amortization

 

Net

 

Amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Developed technology

 

$

14,941

 

$

(5,476

)

$

9,465

 

Customer relationships

 

 

7,159

 

 

(1,006

)

 

6,153

 

Supplier relationships

 

 

2,881

 

 

(500

)

 

2,381

 

Trade name

 

 

60

 

 

(60

)

 

 

Patent

 

 

1,878

 

 

(108

)

 

1,770

 

​  

​  

​  

​  

​  

​  

Total amortizable intangible assets

 

 

26,919

 

 

(7,150

)

 

19,769

 

​  

​  

​  

​  

​  

​  

Non-amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Domain names

 

 

32

 

 

 

 

32

 

Trademarks

 

 

263

 

 

 

 

263

 

​  

​  

​  

​  

​  

​  

Total

 

$

27,214

 

$

(7,150

)

$

20,064

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

                                                                                                                                                                                                

 

 

As of December 31, 2016

 

 

 

Gross

 

Accumulated
Amortization

 

Net

 

Amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Developed technology

 

$

9,400

 

$

(1,140

)

$

8,260

 

Customer relationships

 

 

400

 

 

(148

)

 

252

 

Trade name

 

 

60

 

 

(56

)

 

4

 

Patent

 

 

1,512

 

 

(55

)

 

1,457

 

​  

​  

​  

​  

​  

​  

Total amortizable intangible assets

 

 

11,372

 

 

(1,399

)

 

9,973

 

​  

​  

​  

​  

​  

​  

Non-amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Domain names

 

 

32

 

 

 

 

32

 

Trademarks

 

 

263

 

 

 

 

263

 

​  

​  

​  

​  

​  

​  

Total

 

$

11,667

 

$

(1,399

)

$

10,268

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        Amortization expense was $5.7 million, $0.9 million and $0.5 million for the years ended December 31, 2017, 2016 and 2015, respectively.

        Total estimated future amortization expense was as follows (in thousands):

                                                                                                                                                                                                

 

 

As of
December 31,
2017

 

2018

 

$

6,793

 

2019

 

 

5,083

 

2020

 

 

2,653

 

2021

 

 

1,520

 

2022

 

 

924

 

Thereafter

 

 

2,796

 

​  

​  

Total

 

$

19,769

 

​  

​  

​  

​  

 

Accrued Expenses and Other Liabilities
Accrued Expenses and Other Liabilities

7. Accrued Expenses and Other Liabilities

        Accrued expenses and other current liabilities consisted of the following (in thousands):

                                                                                                                                                                                                

 

 

As of
December 31,

 

 

 

2017

 

2016

 

Accrued payroll and related

 

$

4,898

 

$

3,132

 

Accrued bonus and commission

 

 

4,777

 

 

2,251

 

Accrued cost of revenue

 

 

10,876

 

 

8,741

 

Sales and other taxes payable

 

 

20,877

 

 

28,795

 

ESPP contributions

 

 

1,338

 

 

4,365

 

Deferred rent

 

 

1,048

 

 

1,250

 

Accrued other expense

 

 

9,800

 

 

10,774

 

​  

​  

​  

​  

Total accrued expenses and other current liabilities

 

$

53,614

 

$

59,308

 

​  

​  

​  

​  

​  

​  

​  

​  

        Long-term liabilities consisted of the following (in thousands):

                                                                                                                                                                                                 

 

 

As of
December 31,

 

 

 

2017

 

2016

 

Deferred rent

 

$

8,480

 

$

9,387

 

Deferred tax liability

 

 

2,452

 

 

(2)

 

Accrued other expense

 

 

477

 

 

158

 

​  

​  

​  

​  

Total long-term liabilities

 

$

11,409

 

$

9,543

 

​  

​  

​  

​  

​  

​  

​  

​  

 

Supplemental Balance Sheet Information
Supplemental Balance Sheet Information

8. Supplemental Balance Sheet Information

        A roll-forward of the Company's reserves for the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands):

 

 

 

           

(a)          

Allowance for doubtful accounts:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Balance, beginning of period

 

$

1,076

 

$

486

 

$

210

 

Additions

 

 

580

 

 

1,145

 

 

705

 

Write-offs

 

 

(623

)

 

(555

)

 

(429

)

​  

​  

​  

​  

​  

​  

Balance, end of period

 

$

1,033

 

$

1,076

 

$

486

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

 

 

           

(b)          

Sales credit reserve:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Balance, beginning of period

 

$

544

 

$

714

 

$

312

 

Additions

 

 

2,531

 

 

1,348

 

 

1,210

 

Deductions against reserve

 

 

(1,314

)

 

(1,518

)

 

(808

)

​  

​  

​  

​  

​  

​  

Balance, end of period

 

$

1,761

 

$

544

 

$

714

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Revenue by Geographic Area
Revenue by Geographic Area

9. Revenue by Geographic Area

        Revenue by geographic area is based on the IP address at the time of registration. The following table sets forth revenue by geographic area (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Revenue by geographic area:

 

 

 

 

 

 

 

 

 

 

United States

 

$

308,612

 

$

233,922

 

$

143,145

 

International

 

 

90,408

 

 

43,413

 

 

23,774

 

​  

​  

​  

​  

​  

​  

Total

 

$

399,020

 

$

277,335

 

$

166,919

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Percentage of revenue by geographic area:

 

 

 

 

 

 

 

 

 

 

United States

 

 

77

%

 

84

%

 

86

%

International

 

 

23

%

 

16

%

 

14

%

        Long-lived assets outside the United States were not significant.

 

Commitments and Contingencies
Commitments and Contingencies

10. Commitments and Contingencies

 

 

 

           

(a)          

Lease Commitments

        The Company entered into various non-cancelable operating lease agreements for its facilities that expire over the next six years. Certain operating leases contain provisions under which monthly rent escalates over time. When lease agreements contain escalating rent clauses or free rent periods, the Company recognizes rent expense on a straight-line basis over the term of the lease.

        In January 2016, the Company entered into a lease agreement ("Lease"), as subsequently amended, for approximately 90,000 square feet of new office space at 375 Beale Street in San Francisco, California, that houses its principal executive office. The term of the Lease is approximately 96 months following the commencement in October 2016, and the lease payments range from $0.4 million per month in the first 60 months to $0.5 million per month thereafter. The Lease included a tenant improvement allowance to cover construction of certain leasehold improvements for up to $8.3 million. All applicable amounts were collected from the landlord as of December 31, 2017. Based on the terms of the landlord incentive and involvement of the Company in the construction process, the leasehold improvements were determined to be property of the Company. The Company secured its lease obligation with a $7.4 million letter of credit, which was designated as restricted cash on its balance sheet as of December 31, 2016. As of December 31, 2017, the letter of credit and the restricted cash were reduced to $5.5 million, as stipulated in the lease agreement.

        Rent expense was $8.1 million, $7.3 million and $4.1 million for the years ended December 31, 2017, 2016 and 2015, respectively.

        Future minimum lease payments under non-cancelable operating leases were as follows (in thousands):

                                                                                                                                                                                    

Year Ending December 31:

 

As of
December 31,
2017

 

2018

 

$

7,884

 

2019

 

 

7,676

 

2020

 

 

7,101

 

2021

 

 

7,033

 

2022

 

 

5,864

 

Thereafter

 

 

10,189

 

​  

​  

Total minimum lease payments

 

$

45,747

 

​  

​  

​  

​  

        Additionally, the Company has noncancellable contractual commitments with its cloud infrastructure provider, network service providers and other vendors that are non-cancellable and expire within one to four years. Future minimum payments under these noncancellable purchase commitments were as follows (in thousands). Unrecognized tax benefits are not included in these amounts because any amounts expected to be settled in cash are not material:

                                                                                                                                                                                    

Year Ending December 31:

 

As of
December 31,
2017

 

2018

 

$

22,414

 

2019

 

 

25,526

 

2020

 

 

147

 

2021

 

 

23

 

​  

​  

Total payments

 

$

48,110

 

​  

​  

​  

​  

 

 

 

 

           

(b)          

Legal Matters

 

        On April 30, 2015, Telesign Corporation, or Telesign, filed a lawsuit against the Company in the United States District Court, Central District of California ("Telesign I"). Telesign alleges that the Company is infringing three U.S. patents that it holds: U.S. Patent No. 8,462,920 ("'920"), U.S. Patent No. 8,687,038 ("'038") and U.S. Patent No. 7,945,034 ("'034"). The patent infringement allegations in the lawsuit relate to the Company's Account Security products, its two-factor authentication use case and an API tool to find information about a phone number. The Company petitioned the U.S. Patent and Trademark Office ("U.S. PTO") for inter partes review of the patents at issue. On July 8, 2016, PTO denied the Company's petition for inter partes review of the '920 and '038 patents, and on June 26, 2017, it upheld the patentability of the '034 patent, adopting Telesign's narrow construction of its patent.

        On March 28, 2016, Telesign filed a second lawsuit against the Company in the United States District Court, Central District of California ("Telesign II"), alleging infringement of U.S. Patent No. 9,300,792 ("'792") held by Telesign. The '792 patent is in the same patent family as the '920 and '038 patents asserted in Telesign I. On March 8, 2017, in response to a petition by the Company, the PTO issued an order instituting the inter partes review for the '792 patent. A final written decision is expected by March 2018. On March 15, 2017, Twilio filed a motion to consolidate and stay related cases pending the conclusion of the '792 patent inter partes review, which the court granted. With respect to each of the patents asserted in Telesign I and Telesign II, the complaints seek, among other things, to enjoin the Company from allegedly infringing the patents, along with damages for lost profits.

        On December 1, 2016, the Company filed a patent infringement lawsuit against Telesign in the United States District Court, Northern District of California, alleging indirect infringement of United States Patent No. 8,306,021, United States Patent No. 8,837,465, United States Patent No. 8,755,376, United States Patent No. 8,736,051, United States Patent No. 8,737,962, United States Patent No. 9,270,833, and United States Patent No. 9,226,217. Telesign filed a motion to dismiss the complaint on January 25, 2017. In two orders, issued on March 31, 2017 and April 17, 2017, the Court granted Telesign's motion to dismiss with respect to the '962, '833, '051 and '217 patents, but denied Telesign's motion to dismiss as to the '021, '465 and '376 patents. This litigation is currently ongoing.

        On February 18, 2016, a putative class action complaint was filed in the Alameda County Superior Court in California, entitled Angela Flowers v. Twilio Inc. The complaint alleges that the Company's products permit the interception, recording and disclosure of communications at a customer's request and are in violation of the California Invasion of Privacy Act. The complaint seeks injunctive relief as well as monetary damages. On May 27, 2016, the Company filed a demurrer to the complaint. On August 2, 2016, the court issued an order denying the demurrer in part and granted it in part, with leave to amend by August 18, 2016 to address any claims under California's Unfair Competition Law. The plaintiff opted not to amend the complaint. Following a period of discovery, the plaintiff filed a motion for class certification on September 20, 2017. On January 2, 2018, the court issued an order granting in part and denying in part the plaintiff's class certification motion. The court certified two classes of individuals who, during specified time periods, allegedly sent or received certain communications involving the accounts of three of the Company's customers that were recorded. The court has not yet set a schedule for notice to potential class members, additional discovery, summary judgment motions, or trial.

        The Company intends to vigorously defend itself against these lawsuits and believes it has meritorious defenses to each matter in which it is a defendant. It is too early in these matters to reasonably predict the probability of the outcomes or to estimate ranges of possible losses.

        In addition to the litigation matters discussed above, from time to time, the Company is a party to legal action and subject to claims that arise in the ordinary course of business. The claims are investigated as they arise and loss estimates are accrued, when probable and reasonably estimable. While it is not feasible to predict or determine the ultimate outcome of these matters, the Company believes that these legal proceedings will not have a material adverse effect on its financial position or results of operations.

        Legal fees and other costs related to litigation and other legal proceedings are expensed as incurred and are included in general and administrative expenses in the accompanying consolidated statements of operations.

 

 

 

           

(c)          

Indemnification Agreements

        The Company has signed indemnification agreements with all of its board members and executive officers. The agreements indemnify the board members and executive officers from claims and expenses on actions brought against the individuals separately or jointly with the Company for certain indemnifiable events. Indemnifiable Events generally mean any event or occurrence related to the fact that the board member or the executive officer was or is acting in his or her capacity as a board member or an executive officer for the Company or was or is acting or representing the interests of the Company.

        In the ordinary course of business, the Company enters into contractual arrangements under which it agrees to provide indemnification of varying scope and terms to business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements, intellectual property infringement claims made by third parties and other liabilities relating to or arising from the Company's various products, or its acts or omissions. In these circumstances, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, the Company's obligations under these agreements may be limited in terms of time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments. The terms of such obligations may vary.

        As of December 31, 2017 and 2016, no amounts were accrued.

 

 

 

           

(d)          

Other Taxes

        The Company conducts operations in many tax jurisdictions throughout the United States. In many of these jurisdictions, non-income-based taxes, such as sales and use and telecommunications taxes are assessed on the Company's operations. Prior to March 2017, the Company had not billed nor collected these taxes from its customers and, in accordance with U.S. GAAP, recorded a provision for its tax exposure in these jurisdictions when it was both probable that a liability had been incurred and the amount of the exposure could be reasonably estimated. These estimates included several key assumptions including, but not limited to, the taxability of the Company's services, the jurisdictions in which its management believes it has nexus, and the sourcing of revenues to those jurisdictions. Starting in March 2017, the Company began collecting these taxes from customers in certain jurisdictions, and since then, has expanded the number of jurisdictions where these taxes are being collected. The Company expects to continue to expand the number of jurisdictions where these taxes will be collected in the future. Simultaneously, the Company was and continues to be in discussions with certain states regarding its prior state sales and other taxes, if any, that the Company may owe.

        During 2017, the Company revised its estimates of its tax exposure based on settlements reached with various states indicating that certain revisions to the key assumptions including, but not limited to, the sourcing of revenue and the taxability of the Company's services were appropriate in the current period. In the year ended December 31, 2017, the total impact of these changes on the net loss attributable to common stockholders was a reduction of $13.4 million. As of December 31, 2017 and 2016, the liability recorded for these taxes was $20.9 million and $28.8 million, respectively.

        In the event other jurisdictions challenge management's assumptions and analysis, the actual exposure could differ materially from the current estimates.

Stockholders' Equity
Stockholders' Equity

11. Stockholders' Equity

 

 

 

           

(a)          

Convertible Preferred Stock

        As of December 31, 2015, the Company had outstanding Series A, B, C, D, E and T convertible preferred stock (individually referred to as "Series A, B, C, D, E or T" or collectively "Preferred Stock") as follows (in thousands, except share data).

        Immediately prior to the completion of the IPO, all shares of convertible preferred stock then outstanding were automatically converted into 54,508,441 shares of common stock on a one-to-one basis, and then reclassified as shares of Class B common stock.

                                                                                                                                                                                    

 

 

As of December 31, 2015

 

 

 

Shares
Authorized

 

Shares Issued
and
Outstanding

 

Aggregate
Liquidation
preference

 

Proceeds, Net
of Issuance
Costs

 

Series A

 

 

13,173,240

 

 

13,076,491

 

$

4,590

 

$

4,592

 

Series B

 

 

11,416,062

 

 

11,146,895

 

 

11,717

 

 

11,658

 

Series C

 

 

8,452,864

 

 

8,452,864

 

 

25,250

 

 

25,196

 

Series D

 

 

9,440,324

 

 

9,440,324

 

 

70,000

 

 

69,930

 

Series E

 

 

11,494,249

 

 

11,494,249

 

 

130,000

 

 

125,448

 

Series T

 

 

5,000,000

 

 

897,618

(1)

 

9

 

 

(2)

​  

​  

​  

​  

​  

​  

​  

​  

Total

 

 

58,976,739

 

 

54,508,441

 

$

241,566

 

$

236,824

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  


 

 

 

(1)          

The outstanding shares include 687,885 shares held in escrow as of December 31, 2015 related to the Authy acquisition. Of these shares, 507,885 shares were subject to graded vesting over a period of three years, as amended, and had a fair value of $4.0 million. A total of 127,054 shares were subject to certain performance conditions and were returned to the issuer in the third quarter 2016 due to the non-fulfillment of certain conditions of the merger agreement. All remaining unvested shares vested in the fourth quarter of 2016.

(2)          

389,733 shares were issued as part of the purchase price for Authy acquisition and had a fair value of $3.1 million on the acquisition closing date.

        The holders of the Company's Preferred Stock had the following rights, preferences and privileges:

Conversion

        At any time following the date of issuance, each share of Preferred Stock is convertible, at the option of its holder, into the number of shares of common stock which results from dividing the applicable original issue price per share for each series by the applicable conversion price per share for such series, on the date of conversion. As of December 31, 2015, the initial conversion prices per share of all series of preferred stock were equal to the original issue prices of each series and therefore the conversion ratio was 1:1.

        Each share of preferred stock shall be automatically converted into shares of common stock immediately upon the earlier of (i) the consummation of a firmly underwritten public offering pursuant to the Securities Act of 1933, as amended, the public offering price of which is not less than $50.0 million in aggregate; or (ii) the date specified by the written consent of holders of a majority of the outstanding shares of preferred stock, voting together as a class of shares on an as-converted basis. In addition, the conversion of each of the Series B, Series C, Series D and Series E preferred stock in connection with a Liquidation Event defined below requires the written consent of a majority of such series, if the proceeds payable to each of these series is less than the respective original issuance price.

        A Liquidation Event includes (i) a sale, lease or other disposition of all or substantially all of the Company's assets, (ii) a merger or consolidation of the Company into another entity (except where the merger results in the holders of the Company's stock prior to merger continuing to hold at least 50% of the voting power of the capital stock of the Company or the surviving or acquiring entity), (iii) the transfer of the Company's securities to a person, or a group of affiliated persons, if, after such a transfer, such person or group of persons holds 50% or more of the outstanding voting stock of the Company, (iv) the grant of an exclusive, irrecoverable license to all or substantially all of the Company's intellectual property or (v) a liquidation, dissolution or winding up of the Company.

        In the event the Company issues any additional stock, as defined in the Company's Certificate of Incorporation, after the preferred stock original issue date, without consideration or for a consideration per share less than the conversion price applicable to a series of preferred stock in effect immediately prior to such issuance, the conversion price for such series in effect immediately prior to each such issuance shall be adjusted according to a formula set forth in the Company's Certificate of Incorporation.

Voting

        The holders of Preferred Stock and the holders of common stock vote together and not as separate classes, except in cases specifically provided for in the Certificate of Incorporation or as provided by law.

        The holders of each share of Preferred Stock has the right to one vote for each share of common stock into which such Preferred Stock could be converted, and, with respect to such vote, holders of Preferred Stock have full voting rights and powers equal to the voting rights and powers of the holders of common stock, with the exception of voting for the election of directors referred to below.

        As long as a majority of the shares of Series A preferred stock originally issued remain outstanding, the holders of such shares, voting as a separate class, shall be entitled to elect one director. As long as a majority of the shares of Series B preferred stock originally issued remain outstanding, the holders of such shares, voting as a separate class, shall be entitled to elect one director. As long as at least 2,000,000 shares of Series D preferred stock are outstanding, the holders of such shares, voting as a separate class, shall be entitled to elect one director. The holders of common stock, voting as a separate class, shall be entitled to elect two directors. The holders of shares of Preferred Stock and common stock, voting together as a single class on an as-converted basis, shall be entitled to elect the remaining directors of the Company.

Dividends

        The holders of convertible preferred stock are entitled to receive, when and if declared by the board of directors, out of any assets legally available therefor, any dividends as may be declared from time to time by the board of directors. No dividend may be declared or paid on the common stock unless any and all such dividends are distributed among all holders of common stock and preferred stock on a pro rata pari passu basis in proportion to the number of shares of common stock that would be held by each such holder if all shares of preferred stock were converted to common stock at the effective conversion rate. The right to receive dividends on shares of preferred stock is non-cumulative. No dividends had been declared or paid by the Company as of December 31, 2015 and through the Company's IPO.

Liquidation Preference

        In the event of any Liquidation Event of the Company, the holders of Series A, Series B, Series C, Series D and Series E preferred stock ("senior preferred stock") shall be entitled to receive, in preference to any distribution of the proceeds to the holders of Series T preferred stock or common stock, an amount per share equal to the sum of the applicable original issue price for each series of preferred stock (as adjusted for stock splits and combinations as described in the Certificate of Incorporation), plus declared but unpaid dividends on such share. Upon completion of this distribution, the holders of Series T preferred stock shall be entitled to receive in preference to any distribution of the proceeds to the holders of common stock an amount per share equal to the sum of the applicable original issue price for Series T preferred stock, plus declared but unpaid dividends on such share. If the proceeds thus distributed among the holders of the preferred stock are insufficient to permit payment to such holders of the full preferential amounts, then the entire proceeds available for distribution shall be distributed ratably first among the holders of the senior preferred stock in proportion to the full preferential amount that each holder is otherwise entitled to. The original issue price per share of Series A, Series B, Series C, Series D, Series E and Series T convertible preferred stock is equal to $0.35, $1.05, $2.99, $7.42, $11.31 and $0.01, respectively.

        Upon completion of the distribution referred to above, all the remaining proceeds available for distribution shall be distributed to the holders of the Company's common stock pro rata based on the number of common stock held by each.

        The Company classified the Preferred Stock within shareholders' equity since the shares are not redeemable, and the holders of the Preferred Stock cannot effect a deemed liquidation of the Company outside of the Company control.

 

 

 

           

(b)          

Preferred Stock

        As of December 31, 2017 and 2016, the Company had authorized 100,000,000 shares of preferred stock, par value $0.001, of which no shares were issued and outstanding.

 

 

 

           

(c)          

Common Stock

        As of December 31, 2017 and 2016, the Company had authorized 1,000,000,000 shares of Class A common stock and 100,000,000 shares of Class B common stock, each par value $0.001 per share. As of December 31, 2017, 69,906,550 shares of Class A common stock and 24,063,246 shares of Class B common stock were issued and outstanding. As of December 31, 2016, 49,996,410 shares of Class A common stock and 37,252,138 shares of Class B common stock were issued and outstanding. Holders of Class A and Class B common stock are entitled to one vote per share and 10 votes per share, respectively, and the shares of Class A common stock and Class B common stock are identical, except for voting and conversion rights. The outstanding Class B common stock in both periods included 180,000 shares related to the Authy acquisition that were held in escrow.

        The Company had reserved shares of common stock for issuance as follows:

                                                                                                                                                                                    

 

 

As of December 31,

 

 

 

2017

 

2016

 

Stock options issued and outstanding

 

 

10,710,427

 

 

14,649,276

 

Nonvested restricted stock units issued and outstanding

 

 

5,665,459

 

 

2,034,217

 

Class A common stock reserved for Twilio.org

 

 

635,014

 

 

680,397

 

Stock-based awards available for grant under 2016 Plan

 

 

10,200,189

 

 

10,143,743

 

Class A common stock reserved for issuance under 2016 ESPP

 

 

235,372

 

 

597,038

 

​  

​  

​  

​  

Total

 

 

27,446,461

 

 

28,104,671

 

​  

​  

​  

​  

​  

​  

​  

​  

 

 

 

 

           

(d)          

Stock Repurchases

 

        Following the closing of the Series E convertible preferred stock financing, on August 21, 2015, the Company repurchased an aggregate of 365,916 shares of Series A preferred stock and Series B preferred stock from certain preferred stockholders, and repurchased an aggregate of 1,869,156 shares of common stock from certain current and former employees for $22.8 million in cash, which transaction is referred to as the 2015 Repurchase. The 2015 Repurchase was conducted at a price in excess of the fair value of the Company's common stock at the date of repurchase. No special rights or privileges were conveyed to the employees and former employees. However, not all employees were invited to participate in the 2015 Repurchase. The Company recorded a compensation expense in the amount of $2.0 million for the year ended December 31, 2015, which was the excess of the common stock repurchase price above the fair value of the common stock on the date of repurchase. Of this expense, $0.8 million, $0.1 million and $1.1 million were classified as research and development, sales and marketing and general and administrative expenses, respectively, in the accompanying consolidated statement of operations. The excess of the preferred stock repurchase price above the carrying value of the preferred stock was recorded as a deemed dividend in the year ended December 31, 2015. The Company retired the shares repurchased in the 2015 Repurchase as of August 21, 2015.

 

 

 

           

(e)          

Twilio.org

        On September 2, 2015, the Company's board of directors approved the establishment of Twilio.org with 888,022 shares of the Company's common stock, which at the time represented 1% of the Company's outstanding capital stock on as-converted basis, reserved to fund Twilio.org's activities. Through Twilio.org, which is a part of the Company and not a separate legal entity, the Company donates and discounts its products to nonprofits, who use the Company's products to engage their audience, expand their reach and focus on making a meaningful change in the world. On May 13, 2016, the Company's board of directors authorized a reduction of 107,625 shares reserved to offset equity grants to Twilio.org employees. On October 20, 2016, the Company completed its follow-on public offering. Of the net proceeds the Company received in the offering, $3.9 million was reserved to fund and support the operations of Twilio.org and the number of shares of Class A common stock reserved for Twilio.org was reduced by 100,000. In December 2016, Twilio.org donated the full $3.9 million proceeds into an independent Donor Advised Fund to further the philanthropic goals of the Company. In November 2017, Twilio.org donated 45,383 shares of Class A common stock with a fair value of $1.2 million into the same Donor Advised Fund. Both donations were recorded as charitable contributions in the accompanying consolidated statements of operations. As of December 31, 2017, the total remaining shares reserved for Twilio.org was 635,014.

Stock-Based Compensation
Stock-Based Compensation

12. Stock-Based Compensation

2008 Stock Option Plan

        The Company maintained a stock plan, the 2008 Stock Option Plan, as amended and restated (the "2008 Plan"), which allowed the Company to grant incentive ("ISO"), non-statutory ("NSO") stock options and restricted stock units ("RSU") to its employees, directors and consultants to participate in the Company's future performance through stock-based awards at the discretion of the board of directors. Under the 2008 Plan, options to purchase the Company's common stock could not be granted at a price less than fair value in the case of ISOs and NSOs. Fair value was determined by the board of directors, in good faith, with input from valuation consultants. On June 22, 2016, the plan was terminated in connection with the Company's IPO. Accordingly, no shares are available for future issuance under the 2008 Plan. The 2008 Plan continues to govern outstanding equity awards granted thereunder. The Company's right of first refusal for outstanding equity awards granted under the 2008 Plan terminated upon completion of the IPO. Options granted include provisions for early exercisability.

2016 Stock Option Plan

        The Company's 2016 Stock Option and Incentive Plan (the "2016 Plan") became effective on June 21, 2016. The 2016 Plan provides for the grant of ISOs, NSOs, restricted stock, RSUs, stock appreciation rights, unrestricted stock awards, performance share awards, dividend equivalent rights and cash-based awards to employees, directors and consultants of the Company. A total of 11,500,000 shares of the Company's Class A common stock were initially reserved for issuance under the 2016 Plan. These available shares automatically increase each January 1, beginning on January 1, 2017, by 5% of the number of shares of the Company's Class A and Class B common stock outstanding on the immediately preceding December 31, or such lesser number of shares as determined by the Company's compensation committee. On January 1, 2017, the shares available for grant under the 2016 Plan were automatically increased by 4,362,427 shares.

        Under the 2016 Plan, the stock options are granted at a price per share not less than 100% of the fair market value per share of the underlying common stock on the date of grant. Under both plans, stock options generally expire 10 years from the date of grant and vest over periods determined by the board of directors. The vesting period for new-hire options and restricted stock units is generally a four-year term from the date of grant, at a rate of 25% after one year, then monthly or quarterly, respectively, on a straight-line basis thereafter. In July 2017, the Company began granting restricted stock units to existing employees that vest in equal quarterly installments over a four year service period.

2016 Employee Stock Purchase Plan

        The Company's Employee Stock Purchase Plan ("2016 ESPP") became effective on June 21, 2016. A total of 2,400,000 shares of the Company's Class A common stock were initially reserved for issuance under the 2016 ESPP. These available shares will automatically increase each January 1, beginning on January 1, 2017, by the lesser of 1,800,000 shares of the common stock, 1% of the number of shares of the Company's Class A and Class B common stock outstanding on the immediately preceding December 31 or such lesser number of shares as determined by the Company's compensation committee. On January 1, 2017, the shares available for grant under the 2016 Plan were automatically increased by 872,485 shares.

        The 2016 ESPP allows eligible employees to purchase shares of the Company's Class A common stock at a discount of up to 15% through payroll deductions of their eligible compensation, subject to any plan limitations. Except for the initial offering period, the 2016 ESPP provides for separate six-month offering periods beginning in May and November of each fiscal year, starting in May 2017.

        On each purchase date, eligible employees will purchase the Company's stock at a price per share equal to 85% of the lesser of (i) the fair market value of the Company's Class A common stock on the offering date or (ii) the fair market value of the Company's Class A common stock on the purchase date.

        In the year ended December 31, 2017, 794,142 shares of Class A common stock were purchased under the 2016 ESPP and 235,372 shares are expected to be purchased in the second quarter of 2018. As of December 31, 2017, total unrecognized compensation cost related to the 2016 ESPP was $1.1 million, which will be amortized over a weighted-average period of 0.4 years. No ESPP shares were purchased in the year ended December 31, 2016.

        Stock options activity under the 2008 Plan and 2016 Plan was as follows:

Stock Options

                                                                                                                                                                                    

 

 

Number of
options
outstanding

 

Weighted-
average
exercise
price
(per share)

 

Weighted-
average
remaining
contractual
term
(in years)

 

Aggregate
intrinsic
value
(in thousands)

 

Outstanding options as of December 31, 2016

 

 

14,649,276

 

$

6.14

 

 

7.52

 

$

332,716

 

Granted

 

 

1,526,450

 

 

30.66

 

 

 

 

 

 

 

Exercised

 

 

(5,194,905

)

 

4.93

 

 

 

 

 

 

 

Forfeited and cancelled

 

 

(825,394

)

 

7.76

 

 

 

 

 

 

 

​  

​  

Outstanding options as of December 31, 2017

 

 

10,155,427

 

$

10.31

 

 

7.12

 

$

145,763

 

​  

​  

​  

​  

Options vested and exercisable as of December 31, 2017

 

 

5,278,003

 

$

5.53

 

 

6.28

 

$

95,354

 

​  

​  

​  

​  

        Aggregate intrinsic value represents the difference between the Company's estimated fair value of its common stock and the exercise price of outstanding "in-the-money" options. Prior to the IPO, the fair value of the Company's common stock was estimated by the Company's board of directors. After the IPO, the fair value of the Company's common stock is the Company's Class A common stock price as reported on the New York Stock Exchange. The aggregate intrinsic value of stock options exercised was $132.0 million, $54.4 million and $10.1 million, during the years ended December 31, 2017, 2016 and 2015, respectively.

        The total estimated grant date fair value of options vested was $15.8 million, $15.3 million and $8.2 million during the years ended December 31, 2017, 2016 and 2015, respectively. The weighted-average grant-date fair value of options granted was $13.33, $5.52 and $4.30 during the years ended December 31, 2017, 2016 and 2015, respectively.

        On February 28, 2017, the Company granted a total of 555,000 shares of performance-based stock options in three distinct awards to an employee with grant date fair values of $13.48, $10.26 and $8.41 per share for a total grant value of $5.9 million. The first half of each award vests upon satisfaction of a performance condition and the remainder vests thereafter in equal monthly installments over a 24-month period. The achievement window expires after 4.3 years from the date of grant and the stock options expire seven years after the date of grant. The stock options are amortized over a derived service period, as adjusted, of 3.4 years, 4.6 years and 5.3 years, respectively. The stock options value and the derived service period were estimated using the Monte-Carlo simulation model. The following table summarizes the details of the performance options:

                                                                                                                                                                                    

 

 

Number of
options
outstanding

 

Weighted-
average
exercise
price
(per share)

 

Weighted-
average
remaining
contractual
term
(in years)

 

Aggregate
intrinsic
value
(in thousands)

 

Outstanding options as of December 31, 2016

 

 

 

$

 

 

 

$

 

Granted

 

 

555,000

 

 

31.72

 

 

 

 

 

 

 

Exercised

 

 

 

 

 

 

 

 

 

 

 

Forfeited and cancelled

 

 

 

 

 

 

 

 

 

 

 

​  

​  

Outstanding options as of December 31, 2017

 

 

555,000

 

$

31.72

 

 

6.0

 

$

 

​  

​  

​  

​  

Options vested and exercisable as of December 30, 2017

 

 

 

$

 

 

 

$

 

​  

​  

​  

​  

        As of December 31, 2017, total unrecognized compensation cost related to nonvested stock options was $34.8 million, which will be amortized on a ratable basis over a weighted-average period of 2.12 years.

Restricted Stock Units

                                                                                                                                                                                    

 

 

Number of
options
outstanding

 

Weighted-
average
grant date
fair value
(per share)

 

Aggregate
intrinsic
value
(in thousands)

 

Nonvested RSUs as of December 31, 2016

 

 

2,034,217

 

$

32.66

 

$

58,687

 

Granted

 

 

4,826,508

 

 

28.05

 

 

 

 

Vested

 

 

(711,371

)

 

30.29

 

 

 

 

Forfeited and cancelled

 

 

(483,895

)

 

29.53

 

 

 

 

​  

​  

Nonvested RSUs as of December 31, 2017

 

 

5,665,459

 

$

29.29

 

$

133,648

 

​  

​  

​  

​  

        Prior to the completion of the Company's IPO, the Company granted RSUs ("Pre-IPO RSUs") under its 2008 Plan to its employees that vested upon the satisfaction of both a time-based service condition and a liquidity condition. The time-based service condition for the majority of these awards will be satisfied over a period of four years. The liquidity condition was satisfied upon occurrence of the Company's IPO in June 2016. RSUs granted on or after the completion of the Company's IPO ("Post-IPO RSUs") are granted under the 2016 Plan and are subject to a time-based vesting condition only. The compensation expense related to these grants is based on the grant date fair value of the RSUs and is recognized on a ratable basis over the applicable service period. The majority of Post-IPO RSUs are earned over a service period of two to four years.

        As of December 31, 2017, total unrecognized compensation cost related to nonvested RSUs was $148.0 million, which will be amortized over a weighted-average period of 3.3 years.

Equity Awards Granted to Nonemployees

        As of December 30, 2017, there were no nonemployee awards outstanding.

        In September 2016, the Company granted 30,255 restricted stock units to a nonemployee. The award fully vested in August 2017. Total stock-based compensation expense recorded for this award during the years ended December 31, 2017 and 2016, was $0.4 million and $0.6 million, respectively.

        In December 2015, the Company granted 30,000 stock options to another nonemployee. On January 1, 2017 due to the employee status change, the grant was converted into a standard award and the fair value accounting stopped. Total stock-based compensation expense recorded for this award in the year ended December 31, 2016, was $0.3 million.

Early Exercise of Nonvested Options

        Under the 2008 Plan, employees have an option to exercise their stock options prior to vesting. The Company has the right to repurchase, at the original issuance price, any unvested (but issued) common shares upon termination of service of an employee, either voluntarily or involuntarily. The consideration received for an early exercise of a stock option is considered to be a deposit of the exercise price and the related amount is recorded as a liability. The liability is reclassified into stockholders' equity as the stock options vest. As of December 31, 2017 and 2016, the Company recorded a liability of $0.03 million and $0.3 million for 5,214 and 49,580 unvested shares, respectively, that were early exercised by employees and were subject to repurchase at the respective period end. These amounts are reflected in current and non-current liabilities on the Company's consolidated balance sheets.

Valuation Assumptions

        The fair value of employee stock options was estimated on the date of grant using the following assumptions in the Black-Scholes option pricing model:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

2017

 

2016

 

2015

Employee Stock Options

 

 

 

 

 

 

Fair value of common stock

 

$23.60 - $31.96

 

$10.09 - $15.00

 

$7.07 - $10.09

Expected term (in years)

 

6.08

 

6.08

 

6.08

Expected volatility

 

44.3% - 47.6%

 

51.4% - 53.0%

 

47.8% - 54.9%

Risk-free interest rate

 

1.9% - 2.3%

 

1.3% - 1.5%

 

1.4% - 2.0%

Dividend rate

 

0%

 

0%

 

0%

Employee Stock Purchase Plan

 

 

 

 

 

 

Expected term (in years)

 

0.5

 

0.90

 

Expected volatility

 

33.2% - 33.9%

 

52%

 

Risk-free interest rate

 

1.1% - 1.4%

 

0.6%

 

Dividend rate

 

0%

 

0%

 

        The following assumptions were used in the Monte Carlo simulation model to estimate the fair value and the derived service period of the performance options:

                                                                                                                                                                                    

Asset volatility

 

 

40

%

Equity volatility

 

 

45

%

Discount rate

 

 

14

%

Stock price at grant date

 

$

31.72

 

Stock-Based Compensation Expense

        The Company recorded the total stock-based compensation expense as follows (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Cost of revenue

 

$

650

 

$

291

 

$

65

 

Research and development

 

 

22,808

 

 

12,946

 

 

4,046

 

Sales and marketing

 

 

9,822

 

 

4,972

 

 

2,389

 

General and administrative

 

 

16,339

 

 

6,016

 

 

2,377

 

​  

​  

​  

​  

​  

​  

Total

 

$

49,619

 

$

24,225

 

$

8,877

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Net Loss Per Share Attributable to Common Stockholders
Net Loss Per Share Attributable to Common Stockholders

13. Net Loss Per Share Attributable to Common Stockholders

        The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented (in thousands, except per share data):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Net loss attributable to common stockholders

 

$

(63,708

)

$

(41,324

)

$

(38,896

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted

 

 

91,224,607

 

 

53,116,675

 

 

17,746,526

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Net loss per share attributable to common stockholders, basic and diluted

 

$

(0.70

)

$

(0.78

)

$

(2.19

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        The following outstanding shares of common stock equivalents were excluded from the calculation of the diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Convertible preferred stock outstanding

 

 

 

 

 

 

54,508,441

(1)

Stock options issued and outstanding

 

 

10,710,427

 

 

14,649,276

 

 

16,883,837

 

Nonvested restricted stock units issued and outstanding

 

 

5,665,459

 

 

2,034,217

 

 

71,000

 

Class A common stock reserved for Twilio.org

 

 

635,014

 

 

680,397

 

 

888,022

 

Class A common stock committed under 2016 ESPP

 

 

235,372

 

 

597,038

 

 

 

Unvested shares subject to repurchase

 

 

5,214

 

 

49,580

 

 

52,407

 

​  

​  

​  

​  

​  

​  

Total

 

 

17,251,486

 

 

18,010,508

 

 

72,403,707

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  


 

 

 

(1)          

Includes 687,885 shares as of December 31, 2015 of Series T convertible preferred stock related to the Authy acquisition held in escrow.

 

Income Taxes
Income Taxes

14. Income Taxes

        The following table presents domestic and foreign components of loss before income taxes for the periods presented (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

United States

 

$

(46,737

)

$

(14,002

)

$

(23,962

)

International

 

 

(16,266

)

 

(26,996

)

 

(11,420

)

​  

​  

​  

​  

​  

​  

Loss before provision for income taxes

 

$

(63,003

)

$

(40,998

)

$

(35,382

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        Provision for income taxes consists of the following (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Current:

 

 

 

 

 

 

 

 

 

 

Federal

 

$

99

 

$

 

$

 

State

 

 

78

 

 

83

 

 

45

 

Foreign

 

 

823

 

 

214

 

 

213

 

​  

​  

​  

​  

​  

​  

Total

 

 

1,000

 

 

297

 

 

258

 

Deferred:

 

 

 

 

 

 

 

 

 

 

Federal

 

 

28

 

 

2

 

 

(109

)

State

 

 

10

 

 

 

 

 

Foreign

 

 

(333

)

 

27

 

 

(27

)

​  

​  

​  

​  

​  

​  

Total

 

 

(295

)

 

29

 

 

(136

)

​  

​  

​  

​  

​  

​  

Provision for income taxes

 

$

705

 

$

326

 

$

122

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        The following table presents a reconciliation of the statutory federal tax rate and the Company's effective tax rate for the years ended December 31, 2017, 2016 and 2015:

                                                                                                                                                                                    

 

 

Year Ended
December 31,

 

 

 

2017

 

2016

 

2015

 

Tax benefit at federal statutory rate

 

 

34

%

 

34

%

 

34

%

State tax, net of federal benefit

 

 

10

 

 

11

 

 

(3

)

Stock-based compensation

 

 

47

 

 

23

 

 

(8

)

Credits

 

 

8

 

 

2

 

 

4

 

Foreign rate differential

 

 

(8

)

 

(23

)

 

(11

)

Reserve for uncertain tax positions

 

 

 

 

(12

)

 

 

Change in valuation allowance

 

 

(46

)

 

(34

)

 

(14

)

Change in federal statutory rate

 

 

(45

)

 

 

 

 

Other

 

 

(1

)

 

(2

)

 

(2

)

​  

​  

​  

​  

​  

​  

Effective tax rate

 

 

(1

)%

 

(1

)%

 

%

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company's deferred tax assets and liabilities (in thousands):

                                                                                                                                                                                    

 

 

As of December 31,

 

 

 

2017

 

2016

 

2015

 

Deferred tax assets:

 

 

 

 

 

 

 

 

 

 

Net operating loss carryforwards

 

$

56,138

 

$

31,090

 

$

27,401

 

Accrued and prepaid expenses

 

 

9,140

 

 

16,698

 

 

7,603

 

Stock-based compensation

 

 

7,131

 

 

5,368

 

 

1,433

 

Research and development credits

 

 

16,212

 

 

7,807

 

 

6,022

 

Charitable contributions

 

 

1,233

 

 

1,458

 

 

 

Other

 

 

472

 

 

 

 

 

​  

​  

​  

​  

​  

​  

Gross deferred tax assets

 

 

90,326

 

 

62,421

 

 

42,459

 

Valuation allowance

 

 

(78,900

)

 

(49,601

)

 

(35,613

)

​  

​  

​  

​  

​  

​  

Net deferred tax assets

 

 

11,426

 

 

12,820

 

 

6,846

 

Deferred tax liabilities:

 

 

 

 

 

 

 

 

 

 

Capitalized software

 

 

(7,664

)

 

(7,086

)

 

(4,084

)

Prepaid expenses

 

 

(1,015

)

 

(452

)

 

(2,035

)

Acquired intangibles

 

 

(2,101

)

 

(152

)

 

(460

)

Property and equipment

 

 

(2,380

)

 

(4,931

)

 

(240

)

Deferred commissions

 

 

(718

)

 

(201

)

 

 

​  

​  

​  

​  

​  

​  

Net deferred tax asset (liability)

 

$

(2,452

)

$

(2

)

$

27

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        As of December 31, 2017, the Company had approximately $229.3 million in federal net operating loss carryforwards and $12.6 million in federal tax credits. If not utilized, the federal net operating loss and tax credit carryforwards will expire at various dates beginning in 2029.

        As of December 31, 2017, the Company had approximately $159.6 million in state net operating loss carryforwards and $11.0 million in state tax credits. If not utilized, the state net operating loss carryforwards will expire at various dates beginning in 2026. The California state tax credits can be carried forward indefinitely.

        A limitation may apply to the use of the net operating loss and credit carryforwards, under provisions of the Internal Revenue Code of 1986, as amended, and similar state tax provisions that are applicable if the Company experiences an "ownership change." An ownership change may occur, for example, as a result of issuance of new equity. Should these limitations apply, the carryforwards would be subject to an annual limitation, resulting in a potential reduction in the gross deferred tax assets before considering the valuation allowance.

        The Company's accounting for deferred taxes involves the evaluation of a number of factors concerning the realizability of its net deferred tax assets. The Company primarily considered such factors as its history of operating losses, the nature of the Company's deferred tax assets, and the timing, likelihood and amount, if any, of future taxable income during the periods in which those temporary differences and carryforwards become deductible. At present, the Company does not believe that it is more likely than not that the net deferred tax assets will be realized, accordingly, a full valuation allowance has been established. The valuation allowance increased by approximately $29.3 million and $14.0 million during the years ended December 31, 2017 and 2016, respectively.

        A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Unrecognized tax benefit, beginning of year

 

$

12,275

 

$

1,679

 

$

1,024

 

Gross increases for tax positions of prior years

 

 

493

 

 

1,996

 

 

 

Gross decrease for tax positions of prior years

 

 

(6,331

)

 

 

 

 

Gross increases for tax positions of current years

 

 

3,008

 

 

8,600

 

 

655

 

​  

​  

​  

​  

​  

​  

Unrecognized tax benefit, end of year

 

$

9,445

 

$

12,275

 

$

1,679

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

        As of December 31, 2017, the Company had approximately $9.4 million of unrecognized tax benefits. If the $9.4 million is recognized, $0.4 million would affect the effective tax rate. The remaining amount would be offset by the reversal of related deferred tax assets which are subject to a full valuation allowance.

        The Company recognizes interest and penalties, if any, related to uncertain tax positions in its income tax provision. As of December 31, 2017, the Company has accumulated $35,000 in both interest and penalties related to uncertain tax positions.

        The Company does not anticipate any significant changes within 12 months of December 31, 2017, in its uncertain tax positions that would be material to the consolidated financial statements taken as a whole because nearly all of the unrecognized tax benefit has been offset by a deferred tax asset, which has been reduced by a valuation allowance.

        The Company files U.S. federal income tax returns as well as income tax returns in many U.S. states and foreign jurisdictions. As of December 31, 2017, the tax years 2008 through the current period remain open to examination by the major jurisdictions in which the Company is subject to tax. Fiscal years outside the normal statute of limitation remain open to audit by tax authorities due to tax attributes generated in those early years, which have been carried forward and may be audited in subsequent years when utilized. The Company is not currently subject to U.S. federal, state and local, or non-U.S. income tax examinations by any tax authorities.

        On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act ("Tax Act"). The Tax Act makes broad and complex changes to the U.S. tax code including, but not limited to, (1) reducing the U.S. federal corporate tax rate from 35% to 21%; (2) requiring companies to pay a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries; (3) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries; (4) requiring current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations; (5) eliminating the corporate alternative minimum tax (AMT) and changing how existing AMT credits can be realized; (6) creating the base erosion anti-abuse tax (BEAT), a new minimum tax; (7) creating a new limitation on deductible interest expense; and (8) changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017.

        We remeasured certain deferred tax assets and liabilities based on rates at which they are expected to reverse in the future, which is generally 21%. The rate reduction would generally take effect on January 1, 2018. Consequently, any changes in the US corporate income tax rate will impact the carrying value of our deferred tax assets. Under the new corporate income tax rate of 21%, U.S. federal and state deferred tax assets will decrease by approximately $28.0 million and the valuation allowance will decrease by approximately $28.0 million. Due to the valuation allowance on the deferred tax assets, the provisional amount recorded related to the remeasurement was zero.

        The SEC staff issued SAB 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Act for which the accounting under ASC 740 is complete. To the extent that a company's accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act.

        Our accounting for the following element of the Tax Act is complete.

        Reduction of U.S. federal corporate tax rate: The Act reduces the corporate tax rate to 21%, effective January 1, 2018. Consequently, we have recorded a decrease to our federal and state deferred tax assets of $28.0 million, with a corresponding net adjustment to valuation allowance of $28.0 million for the year ended December 31, 2017.

        Our accounting for the following elements of the Tax Act is incomplete, and we were not yet able to make reasonable estimates of the effects. Therefore, no provisional adjustments were recorded.

        Indefinite reinvestment assertion:    Although the mandatory deemed repatriation tax has removed U.S. federal taxes on distributions to the U.S., the Company continues to evaluate the expected manner of recovery to determine whether or not to continue to assert indefinite reinvestment on a part or all the foreign undistributed earnings. This requires the Company to re-evaluate its reinvestment policies in light of the 2017 Act and calculate the tax cost that is incremental to the deemed repatriation tax, (e.g. foreign withholding, state income taxes of repatriating cash to the U.S. While the provisional tax expense for the year ended December 31, 2017 is based upon an assumption that foreign undistributed earnings are indefinitely reinvested, the Company's plan may change upon the completion of the analysis of the impact of the 2017 Act and completion of the calculation of the incremental tax effects on the repatriation of foreign undistributed earnings. In the event the Company determines not to continue to assert the permanent reinvestment of part or all of foreign undistributed earnings, such a determination could result in the accrual and payment of additional foreign, state and local taxes.

        Global intangible low taxed income (GILTI): The Tax Act creates a new requirement that certain income (i.e., GILTI) earned by controlled foreign corporations (CFCs) must be included currently in the gross income of the CFCs' U.S. shareholder. GILTI is the excess of the shareholder's "net CFC tested income" over the net deemed tangible income return, which is currently defined as the excess of (1) 10% of the aggregate of the U.S. shareholder's pro rata share of the qualified business asset investment of each CFC with respect to which it is a U.S. shareholder over (2) the amount of certain interest expense taken into account in the determination of net CFC-tested income.

        Because of the complexity of the new GILTI tax rules, we are continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the "period cost method") or (2) factoring such amounts into a company's measurement of its deferred taxes (the "deferred method"). Our selection of an accounting policy with respect to the new GILTI tax rules will depend, in part, on analyzing our global income to determine whether we expect to have future U.S. inclusions in taxable income related to GILTI and, if so, what the impact is expected to be. Because whether we expect to have future U.S. inclusions in taxable income related to GILTI depends on not only our current structure and estimated future results of global operations but also our intent and ability to modify our structure and/or our business, we are not yet able to reasonably estimate the effect of this provision of the Tax Act. Therefore, we have not made any adjustments related to potential GILTI tax in our financial statements and have not made a policy decision regarding whether to record deferred taxes on GILTI.

Employee Benefit Plan
Employee Benefit Plan

15. Employee Benefit Plan

        The Company sponsors a 401(k) defined contribution plan covering all employees. There were no employer contributions to the plan in the years ended December 31, 2015. The employer contribution to the plan in the year ended December 31, 2017 and 2016 was $1.8 million and $1.1 million, respectively.

Transactions with Investors
Transactions with Investors

16. Transactions With Investors

        In 2015, two of the Company's vendors participated in the Company's Series E convertible preferred stock financing and owned approximately 1.9% and 1.0% , respectively, of the Company's capital stock, on an as-if converted basis, as of December 31, 2017; 2.0% and 1.0%, respectively, of the Company's capital stock, on as-if converted basis, as of December 31, 2016; and 2.5% and 1.2%, respectively, of the Company's outstanding capital stock as of December 31, 2015.

        During the years ended December 31, 2017, 2016 and 2015, the amounts of software services the Company purchased from the first vendor were $20.4 million, $14.5 million and $11.1 million, respectively. The amounts due to this vendor as of December 31, 2017 and 2016 were $0.2 million and none, respectively. The amount due from this vendor as of December 31, 2017 and 2016 were $1.2 million and $0.3 million, respectively. In October 2016, the Company entered into a three-year agreement with this vendor to purchase services for an aggregate purchase commitment amount of $57.7 million over the course of the three-year contractual period.

        The amount of services the Company purchased from the second vendor was $0.8 million in the year ended December 31, 2017, and $0.5 million for each of the years ended December 31, 2016 and 2015. The amounts due to this vendor as of December 31, 2017 and 2016 were insignificant. The amounts due from this vendor as of December 31, 2017 and 2016 were none and $1.0 million, respectively.

Summary of Significant Accounting Policies (Policies)

 

 

 

         (a)        Basis of Presentation

        The Company's consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP").

 

 

 

         (b)        Principles of Consolidation

        The consolidated financial statements include the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated.

 

 

 

         (c)        Use of Estimates

        The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates are used for, but not limited to, revenue allowances and returns; valuation of the Company's stock and stock-based awards; recoverability of long-lived and intangible assets; capitalization and useful life of the Company's capitalized internal-use software development costs; fair value of acquired intangible assets and goodwill; accruals and contingencies. Estimates are based on historical experience and on various assumptions that the Company believes are reasonable under current circumstances. However, future events are subject to change and best estimates and judgments may require further adjustments; therefore, actual results could differ materially from those estimates. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation.

 

 

 

         (d)        Concentration of Credit Risk

        Financial instruments that potentially expose the Company to a concentration of credit risk consist primarily of cash, cash equivalents, marketable securities, restricted cash and accounts receivable. The Company maintains cash, cash equivalents, restricted cash and marketable securities with financial institutions that management believes are financially sound and have minimal credit risk exposure although the balances will exceed insured limits.

        The Company sells its services to a wide variety of customers. If the financial condition or results of operations of any significant customers deteriorate substantially, operating results could be adversely affected. To reduce credit risk, management performs ongoing credit evaluations of the financial condition of significant customers. The Company does not require collateral from its credit customers and maintains reserves for estimated credit losses on customer accounts when considered necessary. Actual credit losses may differ from the Company's estimates. During the year ended December 31, 2017, there was no customer organization that accounted for more than 10% of the Company's total revenue. During the year ended December 31, 2016, one customer organization represented approximately 14% of the Company's total revenue. During the year ended December 31, 2015, a different customer organization represented approximately 17% of the Company's total revenue.

        As of December 31, 2017, no customer organizations represented more than 10% of the Company's gross accounts receivable. As of December 31, 2016, one customer organization represented approximately 16% of the Company's gross accounts receivable.

 

 

 

         (e)        Revenue Recognition

        The Company derives its revenue primarily from usage-based fees earned from customers accessing the Company's enterprise cloud computing services invoiced or paid monthly. The Company provides services to its customers under pay-as-you-go contracts and term-based contracts ranging in duration from one month to 48 months. Customers that pay via credit card are either billed in advance or as they use service. Larger customers are billed in arrears via invoices for services used. Certain customers have contracts that provide for a minimum monthly commitment and some customers have contracts that provide for a commitment that may be of a quarterly, annual or other specific durations.

        The Company recognizes revenue from these transactions when all of the following criteria are satisfied:

 

 

 

           

•          

there is persuasive evidence of an arrangement; 

           

•          

the service has been or is being provided to the customer; 

           

•          

the amount of the fees to be paid by the customer is fixed or determinable; and 

           

•          

collectability of the fees is reasonably assured.

        Term-based contracts revenue is recognized on a straight-line basis over the contractual term of the arrangement beginning on the date that the service is made available to the customer, provided that all other revenue recognition criteria have been met. Usage-based fees are recognized as delivered.

        The Company's arrangements do not contain general rights of return. However, credits may be issued to customers on a case-by-case basis. The contracts do not provide customers with the right to take possession of the software supporting the applications. Amounts that have been invoiced are recorded in accounts receivable and in revenue or deferred revenue, depending on whether the revenue recognition criteria have been met.

        The reserve for sales credits was $1.8 million and $0.5 million as of December 31, 2017 and 2016, respectively, and is included in accounts receivable, net in the accompanying consolidated balance sheets. The reserve for sales credits is calculated based on historical trends and any specific risks identified in processing transactions. Changes in the reserve are recorded against revenue.

        The Company collects various taxes and fees as an agent in connection with the sale of its services and remits these amounts to the respective taxing authorities. These taxes and fees have been presented on a net basis in the consolidated statements of operations and are recorded as a component of accrued liabilities in the accompanying consolidated balance sheets until remitted to the respective taxing authority.

 

 

 

         (f)        Cost of Revenue

        Cost of revenue consists primarily of costs of communications services purchased from network service providers. Cost of revenue also includes fees to support the Company's cloud infrastructure, personnel costs, such as salaries and stock-based compensation for the customer care and support services employees, and non-personnel costs, such as amortization of capitalized internal-use software development costs.

 

 

 

         (g)        Research and Development Expenses

        Research and development expenses consist primarily of personnel costs, cloud infrastructure fees for staging and development, outsourced engineering services, amortization of capitalized internal-use software development costs and an allocation of general overhead expenses. The Company capitalizes the portion of its software development costs that meets the criteria for capitalization.

 

 

 

         (h)        Internal-Use Software Development Costs

        Certain costs of platform and other software applications developed for internal use are capitalized. The Company capitalizes qualifying internal-use software development costs that are incurred during the application development stage. Capitalization of costs begins when two criteria are met: (i) the preliminary project stage is completed and (ii) it is probable that the software will be completed and used for its intended function. Capitalization ceases when the software is substantially complete and ready for its intended use, including the completion of all significant testing. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional functionality and expenses costs incurred for maintenance and minor upgrades and enhancements. Costs related to preliminary project activities and post-implementation operating activities are also expensed as incurred.

        Capitalized costs of platform and other software applications are included in property and equipment. These costs are amortized over the estimated useful life of the software on a straight-line basis over three years. Management evaluates the useful life of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. The amortization of costs related to the platform applications is included in cost of revenue, while the amortization of costs related to other software applications developed for internal use is included in research and development expenses.

 

 

 

         (i)        Advertising Costs

        Advertising costs are expensed as incurred and were $4.9 million, $3.5 million and $2.9 million in the years ended December 31, 2017, 2016 and 2015, respectively. Advertising costs are included in sales and marketing expenses in the accompanying consolidated statements of operations.

 

 

 

         (j)        Stock-Based Compensation

        All stock-based compensation to employees, including the purchase rights issued under the Company's 2016 Employee Stock Purchase Plan (the "ESPP"), is measured on the grant date based on the fair value of the awards on the date of grant. This cost is recognized as an expense following the ratable attribution method, over the requisite service period, for stock options, and the straight-line attribution method, over the offering period, for the purchase rights issued under the ESPP. The Company uses the Black-Scholes option pricing model to measure the fair value of its stock options and the purchase rights issued under the ESPP. The fair value of the restricted stock units is determined using the fair value of the Company's Class A common stock on the date of grant. Prior to adoption of ASU 2016-09, the stock-based compensation was recorded net of estimated forfeitures.

        In March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-09, "Compensation—Stock Compensation (Topic 718): Improvements to Employee Share -Based Payment Accounting." This new guidance was intended to simplify several areas of accounting for stock-based compensation arrangements, including the income tax impact, classification on the statement of cash flows and forfeitures. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The Company early adopted this guidance in the quarter ended December 31, 2016. The new guidance allows entities to account for forfeitures as they occur. The Company elected to account for forfeitures as they occur and adopted this provision on a modified retrospective basis. The $0.1 million of cumulative prior years' impact as well as the impact on the first three quarters of 2016 of $75,000 was recognized as an increase to stock-based compensation during the quarter ended December 31, 2016, as the impact on prior periods was insignificant. Adoption of all other changes in the new guidance did not have a significant impact on the Company's consolidated financial statements.

        Prior to the IPO, the fair value of the Company's common stock was determined by the estimated fair value of the Company's common stock at the time of grant. After the IPO, the Company uses the market closing price of its Class A common stock as reported on the New York Stock Exchange for the fair value.

        Compensation expense for stock options granted to nonemployees is calculated using the Black-Scholes option pricing model and is recognized in expense over the service period. Compensation expense for nonemployee stock options subject to vesting is revalued at each reporting date until the stock options are vested.

        The Black-Scholes option pricing model requires the use of complex assumptions, which determine the fair value of stock-based awards. These assumptions include:

 

 

 

           

•          

Fair value of the common stock.  Prior to the Company's IPO, the board of directors considered numerous objective and subjective factors to determine the fair value of the Company's common stock at each meeting at which awards are approved. The factors included, but were not limited to: (i) contemporaneous valuations of the Company's common stock by an unrelated third party; (ii) the prices at which the Company sold shares of its convertible preferred stock to outside investors in arms-length transactions; (iii) the rights, preferences and privileges of the Company's convertible preferred stock relative to those of its common stock; (iv) the Company's results of operations, financial position and capital resources; (v) current business conditions and projections; (vi) the lack of marketability of the Company's common stock; (vii) the hiring of key personnel and the experience of management; (viii) the introduction of new products; (ix) the risk inherent in the development and expansion of the Company's products; (x) the Company's stage of development and material risks related to its business; (xi) the fact that the option grants involve illiquid securities in a private company; and (xii) the likelihood of achieving a liquidity event, such as an initial public offering or sale of the Company, in light of prevailing market conditions; 

           

•          

Expected term.  The expected term represents the period that the stock-based awards are expected to be outstanding. The Company uses the simplified calculation of expected term, as the Company does not have sufficient historical data to use any other method to estimate expected term; 

           

•          

Expected volatility.  The expected volatility is derived from an average of the historical volatilities of the common stock of several entities with characteristics similar to those of the Company, such as the size and operational and economic similarities to the Company's principal business operations; 

           

•          

Risk -free interest rate.  The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero coupon U.S. Treasury notes with maturities approximately equal the expected term of the stock-based awards; and 

           

•          

Expected dividend.  The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock.

        If any of the assumptions used in the Black-Scholes model changes, stock-based compensation for future options may differ materially compared to that associated with previous grants.

 

 

 

         (k)        Income Taxes

        The Company accounts for income taxes in accordance with authoritative guidance which requires the use of the asset and liability approach. Deferred tax assets and liabilities are recognized for future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss and tax credit carry-forwards. Deferred tax amounts are determined by using the enacted tax rates expected to be in effect when the temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance reduces the deferred tax assets to the amount that is more likely than not to be realized.

        The Company recognizes the effect of uncertain income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.

        The Company records interest and penalties related to uncertain tax positions in the provision for income taxes in the consolidated statements of operations.

 

 

 

         (l)        Foreign Currency Translation

        The functional currency of the Company's foreign subsidiaries is generally the U.S. dollar. Accordingly, the subsidiaries remeasure monetary assets and liabilities at period-end exchange rates, while non-monetary items are remeasured at historical rates. Revenue and expense accounts are remeasured at the average exchange rate in effect during the year. Remeasurement adjustments are recognized in the consolidated statements of operations as other income or expense in the year of occurrence. Foreign currency transaction gains and losses were insignificant for all periods presented.

        For those entities where the functional currency is a foreign currency, adjustments resulting from translating the financial statements into U.S. dollars are recorded as a component of accumulated other comprehensive income (loss) in stockholders' equity. Monetary assets and liabilities denominated in a foreign currency are translated into US dollars at the exchange rate on the balance sheet date. Revenue and expenses are translated at the weighted average exchange rates during the period. Equity transactions are translated using historical exchange rates. Foreign currency transaction gains and losses are included in other income (expense), net in the consolidated statements of operations.

 

 

 

         (m)        Comprehensive Income (Loss)

        Comprehensive income (loss) refers to net income (loss) and other revenue, expenses, gains and losses that, under generally accepted accounting principles, are recorded as an element of stockholders' equity but are excluded from the calculation of net income (loss).

        For the years ended December 31, 2016 and 2015, the Company's operations did not give rise to any material items includable in comprehensive income (loss), which were not already in net income (loss). Accordingly, for those periods, the Company's comprehensive income (loss) is the same as its net income (loss).

 

 

 

         (n)        Net Loss Per Share Attributable to Common Stockholders

        The Company calculates its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. All series of convertible preferred stock are considered to be participating securities as the holders of the preferred stock are entitled to receive a non-cumulative dividend on a pro rata pari passu basis in the event that a dividend is declared or paid on common stock. Shares of common stock issued upon early exercise of stock options that are subject to repurchase are also considered to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is declared or paid on common stock. Under the two-class method, in periods when the Company has net income, net income attributable to common stockholders is determined by allocating undistributed earnings, calculated as net income less current period convertible preferred stock non-cumulative dividends, between common stock and the convertible preferred stock. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. The Company's basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. The dilutive effect of these potential common shares is reflected in diluted earnings per share by application of the treasury stock method. For purposes of this calculation, convertible preferred stock, options to purchase common stock, unvested restricted stock units, common stock issued subject to future vesting, any shares of stock committed under the ESPP, any shares of stock held in escrow and any shares of stock reserved for future donations are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.

        Since the Company's IPO in 2016, Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder on a one-for-one basis, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Shares of Class A common stock are not convertible.

 

 

 

         (o)        Cash and Cash Equivalents

        The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of funds deposited into money market funds. All credit and debit card transactions that process as of the last day of each month and settle within the first few days of the subsequent month are also classified as cash and cash equivalents as of the end of the month in which they were processed.

 

 

 

        (p)        Restricted Cash

        Restricted cash consists of cash deposited into a savings account with a financial institution as collateral for the Company's obligations under its facility leases of premises located in San Francisco, California. The facility lease for the Company's old office space expired in January 2017 and the facility lease for the Company's new office space expires in October 2024. The restricted cash balances as of December 31, 2017 and December 31, 2016 were $5.5 million and $8.6 million, respectively.

 

 

 

         (q)        Accounts Receivable and Allowance for Doubtful Accounts

        Accounts receivable are recorded net of the allowance for doubtful accounts and the reserve for sales credits. The allowance for doubtful accounts is estimated based on the Company's assessment of its ability to collect on customer accounts receivable. The Company regularly reviews the allowance by considering certain factors such as historical experience, credit quality, age of accounts receivable balances and other known conditions that may affect a customer's ability to pay. In cases where the Company is aware of circumstances that may impair a specific customer's ability to meet their financial obligations, a specific allowance is recorded against amounts due from the customer which reduces the net recognized receivable to the amount the Company reasonably believe will be collected. The Company writes-off accounts receivable against the allowance when a determination is made that the balance is uncollectible and collection of the receivable is no longer being actively pursued. The allowance for doubtful accounts was $1.0 million and $1.1 million as of December 31, 2017 and 2016, respectively.

 

 

 

         (r)        Costs Related to the Public Offerings

        Costs related to the public offerings, which consist of direct incremental legal, printing and accounting fees, are deferred until the offering is completed. Upon completion of the offering, these costs are offset against the offering proceeds within the consolidated statements of stockholders' equity. As of December 31, 2016, the Company recorded in its consolidated statement of stockholders' equity $5.7 million in total offering costs, of which $4.9 million and $0.8 million related to the IPO and the FPO, respectively.

 

 

 

         (s)        Property and Equipment

        Property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful life of the related asset. Maintenance and repairs are charged to expenses as incurred.

        The useful lives of property and equipment are as follows:

                                                                                                                                                                                    

Capitalized software development costs

 

3 years

Office equipment

 

3 years

Furniture and fixtures

 

5 years

Software

 

3 years

Leasehold improvements

 

5 years or remaining lease term

 

 

 

 

         (t)        Intangible Assets

        Intangible assets recorded by the Company are costs directly associated with securing legal registration of patents and trademarks, acquiring domain names and the fair value of identifiable intangible assets acquired in business combinations.

        Intangible assets with determinable economic lives are carried at cost, less accumulated amortization. Amortization is computed over the estimated useful life of each asset on a straight-line basis. The Company determines the useful lives of identifiable intangible assets after considering the specific facts and circumstances related to each intangible asset. Factors the Company considers when determining useful lives include the contractual term of any agreement related to the asset, the historical performance of the asset, the Company's long-term strategy for using the asset, any laws or other local regulations which could impact the useful life of the asset and other economic factors, including competition and specific market conditions. Intangible assets without determinable economic lives are carried at cost, not amortized and reviewed for impairment at least annually.

        The useful lives of the intangible assets are as follows:

                                                                                                                                                                                    

Developed technology

 

3 - 4 years

Customer relationships

 

5 - 8 years

Supplier relationships

 

5 years

Trade names

 

2 years

Patents

 

20 years

Trademarks

 

Indefinite

Domain names

 

Indefinite

 

 

 

 

 

 

 

         (u)        Goodwill

        Goodwill represents excess of the aggregate purchase price over the fair value of net identifiable assets acquired in a business combination. Goodwill is not amortized and is tested for impairment at least annually or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that it operates as one reporting unit and has selected November 30 as the date to perform its annual impairment test. In the valuation of goodwill, management must make assumptions regarding estimated future cash flows to be derived from the Company's business. If these estimates or their related assumptions change in the future, the Company may be required to record impairment for these assets. Management may first evaluate qualitative factors to assess if it is more likely than not that the fair value of a reporting unit is less than its carrying amount and to determine if a two-step impairment test is necessary. Management may choose to proceed directly to the two-step evaluation, bypassing the initial qualitative assessment. The first step of the impairment test involves comparing the fair value of the reporting unit to its net book value, including goodwill. If the net book value exceeds its fair value, then the Company would perform the second step of the goodwill impairment test to determine the amount of the impairment loss. The impairment loss would be calculated by comparing the implied fair value of the goodwill to its net book value. In calculating the implied fair value of goodwill, the fair value of the entity would be allocated to all of the other assets and liabilities based on their fair values. The excess of the fair value of the entity over the amount assigned to other assets and liabilities is the implied fair value of goodwill. An impairment loss would be recognized when the carrying amount of goodwill exceeds its implied fair value. No goodwill impairment charges have been recorded for any period presented.

 

 

 

         (v)        Impairment of Long-Lived Assets

        The Company evaluates long-lived assets, including property and equipment and intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets held and used is measured by a comparison of the carrying amount of an asset or an asset group to estimated undiscounted future net cash flows expected to be generated by the asset or asset group. If such evaluation indicates that the carrying amount of the asset or the asset group is not recoverable, any impairment loss would be equal to the amount the carrying value exceeds the fair value. There was no impairment during the years ended December 31, 2017, 2016 and 2015. The value of the internally-developed software written-off due to abandonment was $0.6 million, $0.7 million and $0.1 million in the years ended December 31, 2017, 2016 and 2015, respectively.

 

 

 

         (w)        Deferred Revenue

        Deferred revenue consists of cash deposits from customers to be applied against future usage and customer billings in advance of revenues being recognized from the Company's contracts. Deferred revenue is generally expected to be recognized during the succeeding 12-month period and is thus recorded as a current liability. Deferred revenue is refunded in cash upon termination of customer accounts.

 

 

 

         (x)        Business Combinations

        The Company recognizes identifiable assets acquired and liabilities assumed at their acquisition date fair values. Goodwill is measured as the excess of the consideration transferred over the fair value of assets acquired and liabilities assumed on the acquisition date. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to accurately value assets acquired and liabilities assumed, these estimates are inherently uncertain and subject to refinement. The authoritative guidance allows a measurement period of up to one year from the date of acquisition to make adjustments to the preliminary allocation of the purchase price. As a result, during the measurement period the Company may record adjustments to the fair values of assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that it identifies adjustments to the preliminary purchase price allocation. Upon conclusion of the measurement period or final determination of the values of the assets acquired and liabilities assumed, whichever comes first, any subsequent adjustments will be recorded to the consolidated statement of operations.

 

 

 

         (y)        Segment Information

        The Company's Chief Executive Officer is the chief operating decision maker, who reviews the Company's financial information presented on a consolidated basis for purposes of allocating resources and evaluating the Company's financial performance. Accordingly, the Company has determined that it operates in a single reporting segment.

 

 

 

         (z)        Fair Value of Financial Instruments

        The Company applies fair value accounting for all financial instruments on a recurring basis. The Company's financial instruments, which include cash, cash equivalents, accounts receivable and accounts payable are recorded at their carrying amounts, which approximate their fair values due to their short-term nature. Restricted cash is long-term in nature and consists of cash in a savings account, hence its carrying amount approximates its fair value. Marketable securities consist of U.S. treasury securities and high credit quality corporate debt securities. All marketable securities are considered to be available-for-sale and recorded at their estimated fair values. Unrealized gains and losses for available-for-sale securities are recorded in other comprehensive income (loss). In valuing these items, the Company uses inputs and assumptions that market participants would use to determine their fair value, utilizing valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs.

        Impairments are considered to be other than temporary if they are related to deterioration in credit risk or if it is likely that the security will be sold before the recovery of its cost basis. Realized gains and losses and declines in value deemed to be other than temporary are determined based on the specific identification method and are reported in other income (expense), net.

        The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows:

 

 

 

           

•          

Level 1 Inputs:  Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. 

           

•          

Level 2 Inputs:  Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. 

           

•          

Level 3 Inputs:  Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date.

        A financial instrument's categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

 

 

 

 

         (aa)        Recent Accounting Pronouncements Not Yet Adopted

        In May 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Updates ("ASU") 2017-09, "Compensation-Stock Compensation (Topic 718), Scope of Modification Accounting", which clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The guidance is effective prospectively for interim and annual periods beginning after December 15, 2017 and early adoption is permitted. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have a material impact on the Company's financial position, results of operations or cash flows.

        In January 2017, the FASB issued ASU 2017-04, "Simplifying the Test for Goodwill Impairment", which removes the second step of the goodwill impairment test that requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This guidance is effective prospectively for interim and annual reporting periods beginning after December 15, 2019. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have a material impact on the Company's financial position, results of operations or cash flows.

        In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805) Clarifying the Definition of a Business", which amends the guidance of FASB Accounting Standards Codification Topic 805, "Business Combinations", adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted under certain circumstances. The Company will adopt this guidance upon its effective date and implement it next time there is a potential business combination.

        In November 2016, the FASB issued ASU 2016-18, "Restricted Cash", which requires a statement of cash flows to explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash and restricted cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted. The Company will adopt this guidance upon its effective date and its impact will be a function of the amounts of restricted cash the Company has at that time and the movements therein.

        In October 2016, the FASB issued ASU 2016-16, "Intra-Entity Transfers Other Than Inventory", which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted. The Company will adopt this guidance upon its effective date. The Company does not expect the adoption of this guidance to have any material impact on the Company's financial position, results of operations or cash flows.

        In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments", which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

        In February 2016, the FASB issued ASU No. 2016-02, "Leases." The standard will affect all entities that lease assets and will require lessees to recognize a lease liability and a right-of-use asset for all leases (except for short-term leases that have a duration of less than one year) as of the date on which the lessor makes the underlying asset available to the lessee. For lessors, accounting for leases is substantially the same as in prior periods. For public companies, the new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. For leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, lessees and lessors must apply a modified retrospective transition approach. While the Company expects the adoption of this standard to result in an increase to the reported assets and liabilities, the Company has not yet determined the full impact that the adoption of this standard will have on its consolidated financial statements and related disclosures.

        In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers". This new guidance will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB issued ASU 2015-14 which deferred, by one year, the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net)" clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, "Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing", clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). In May 2016, the FASB issued ASU 2016-12 "Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients", which amends the guidance on transition, collectability, noncash consideration and the presentation of sales and other similar taxes. ASU 2016-12 clarifies that, for a contract to be considered completed at transition, all (or substantially all) of the revenue must have been recognized under legacy GAAP. In addition, ASU 2016-12 clarifies how an entity should evaluate the collectability threshold and when an entity can recognize nonrefundable consideration received as revenue if an arrangement does not meet the standard's contract criteria. In September 2017, the FASB issued ASU 2017-13, "Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606), Leases (Topic 840), and Leases (Topic 842)". These amendments provide additional clarification and implementation guidance on the previously issued ASUs. These amendments do not change the core principles of the guidance stated in ASU 2014-09, instead they are intended to clarify and improve operability of certain topics included within the revenue standard. In November 2017, the FASB issued ASU 2017-14, which includes amendments to certain SEC paragraphs within the FASB Accounting Standards Codification (Codification). ASU 2017-14 amends the Codification to incorporate SEC Staff Accounting Bulletin (SAB) No. 116 and SEC Interpretive Release on Vaccines for Federal Government Stockpiles (SEC Release No. 33-10403) that bring existing SEC staff guidance into conformity with the FASB's adoption of and amendments to ASC Topic 606, Revenue from Contracts with Customers. The effective date and transition requirements for ASU 2016-08, ASU 2016-10, ASU 2016-12, ASU 2017-13 and ASU 2017-14 are the same as the effective date and transition requirements for ASU 2014-09. The Company has evaluated the potential changes from the adoption of the new standard on its financial statements and disclosures, and is in the process of implementing appropriate changes to its business processes, systems and controls to support revenue recognition and disclosures under the new standard. Based on this evaluation, the Company will adopt the requirements of the new standard in the first quarter of 2018, using the modified retrospective transition method with a cumulative catch adjustment to retained earnings as of January 1, 2018. Under the new standard, based on the Company's preliminary assessment, the Company does not believe there will be material changes to its revenue recognition and the expectation is that the majority of the Company's revenue will continue to be recognized according to the usage by its customers, in the period in which that usage occurs.

        The Company is also assessing the impact of adoption of the new standard on its accounting for sales commissions. The Company's current accounting policy requires capitalization and amortization of the deferred commissions. Under the new standard, the amounts capitalized will be recognized as amortization over the expected customer life. The Company's preliminary assessment of its analyses of the amortizable life of the deferred commissions under the new guidance at three years. Further review of certain commission plans is yet to be completed to finalize the impact on the consolidated statements of financial position, results of operations and cash flows.

        There will not be any significant tax impact to the Company's consolidated statements of operations and consolidated balance sheet relating to the adoption of the new standard as there will be a full valuation allowance due to the Company's history of continued losses.

Summary of Significant Accounting Policies (Tables)

 

                                                                                                                                                                                    

Capitalized software development costs

 

3 years

Office equipment

 

3 years

Furniture and fixtures

 

5 years

Software

 

3 years

Leasehold improvements

 

5 years or remaining lease term

 

 

                                                                                                                                                                                    

Developed technology

 

3 - 4 years

Customer relationships

 

5 - 8 years

Supplier relationships

 

5 years

Trade names

 

2 years

Patents

 

20 years

Trademarks

 

Indefinite

Domain names

 

Indefinite

 

Fair Value Measurements (Tables)

 

        The following tables provide the assets measured at fair value on a recurring basis as of December 31, 2017 and 2016 (in thousands):

                                                                                                                                                                                    

 

 

 

 

 

 

Fair Value Hierarchy as of
December 31, 2017

 

 

 

 

 

Amortized
Cost or
Carrying
Value

 

 

 

 

 

 

 

Net
Unrealized
Losses

 

Aggregate
Fair Value

 

 

 

Level 1

 

Level 2

 

Level 3

 

Financial Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cash and cash equivalents:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Money market funds

 

$

95,432

 

$

 

$

95,432

 

$

 

$

 

$

95,432

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total included in cash and cash equivalents

 

 

95,432

 

 

 

 

95,432

 

 

 

 

 

 

95,432

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Marketable securities:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U.S. Treasury securities

 

 

59,962

 

 

(216

)

 

59,746

 

 

 

 

 

 

59,746

 

Corporate debt securities

 

 

116,223

 

 

(382

)

 

 

 

115,841

 

 

 

 

115,841

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total marketable securities

 

 

176,185

 

 

(598

)

 

59,746

 

 

115,841

 

 

 

 

175,587

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total financial assets

 

$

271,617

 

$

(598

)

$

155,178

 

$

115,841

 

$

 

$

271,019

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

                                                                                                                                                                                    

 

 

 

 

As of December 31, 2016

 

 

 

Total
Carrying
Value

 

 

 

Level I

 

Level 2

 

Level 3

 

Total

 

Financial Assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Money market funds (included in cash and cash equivalents)

 

$

274,135

 

$

274,135

 

$

 

$

 

$

274,135

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Total financial assets

 

$

274,135

 

$

274,135

 

$

 

$

 

$

274,135

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

        The following table summarizes the contractual maturities of marketable securities as of December 31, 2017 (in thousands):

                                                                                                                                                                                    

 

 

Amortized
Cost

 

Aggregate
Fair Value

 

Financial Assets:

 

 

 

 

 

 

 

Less than one year

 

$

108,584

 

$

108,360

 

One to two years

 

 

67,601

 

 

67,227

 

​  

​  

​  

​  

Total

 

$

176,185

 

$

175,587

 

​  

​  

​  

​  

​  

​  

​  

​  

 

Property and Equipment (Tables)

        Property and equipment consisted of the following (in thousands):

                                                                                                                                                                                                

 

 

As of December 31,

 

 

 

2017

 

2016

 

Capitalized internal-use software development costs

 

$

49,177

 

$

28,661

 

Leasehold improvements

 

 

14,246

 

 

14,063

 

Office equipment

 

 

9,652

 

 

5,729

 

Furniture and fixtures

 

 

1,976

 

 

1,576

 

Software

 

 

1,675

 

 

968

 

​  

​  

​  

​  

Total property and equipment

 

 

76,726

 

 

50,997

 

Less: accumulated depreciation and amortization

 

 

(26,185

)

 

(13,445

)

​  

​  

​  

​  

Total property and equipment, net

 

$

50,541

 

$

37,552

 

​  

​  

​  

​  

​  

​  

​  

​  

 

 

The amortization expense was allocated as follows (in thousands):

                                                                                                                                                                                                

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Cost of revenue

 

$

4,788

 

$

3,304

 

$

1,793

 

Research and development

 

 

3,619

 

 

2,182

 

 

1,045

 

​  

​  

​  

​  

​  

​  

Total

 

$

8,407

 

$

5,486

 

$

2,838

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Business Combinations (Tables)

        The following table presents the purchase price allocation, as adjusted, recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Net tangible liabilities

 

$

(3,575

)

Goodwill(1)

 

 

12,837

 

Intangible assets(2)

 

 

13,700

 

​  

​  

Total purchase price

 

$

22,962

 

​  

​  

​  

​  


 

 

 

(1)          

Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer and supplier relationships as well as operational synergies. Goodwill is deductible for tax purposes.

(2)          

Identifiable finite-lived intangible assets were comprised of the following:

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

5,000

 

4

Customer relationships

 

 

6,100

 

7 - 8

Supplier relationships

 

 

2,600

 

5

​  

​  

Total intangible assets acquired

 

$

13,700

 

 

​  

​  

​  

​  

 

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

5,000

 

4

Customer relationships

 

 

6,100

 

7 - 8

Supplier relationships

 

 

2,600

 

5

​  

​  

Total intangible assets acquired

 

$

13,700

 

 

​  

​  

​  

​  

 

        The following table presents the final purchase price allocation recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Intangible assets(1)

 

$

8,100

 

Goodwill(2)

 

 

400

 

​  

​  

Total purchase price

 

$

8,500

 

​  

​  

​  

​  


 

 

 

(1)          

The intangible assets consist of developed technology with the estimated useful life of 3 years on the date of acquisition.

(2)          

The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology and the future development initiatives of the acquired workforce. The goodwill is deductible for tax purposes.

 

        The following table presents the final purchase price allocation recorded in the Company's consolidated balance sheet (in thousands):

                                                                                                                                                                                    

 

 

Total

 

Net tangible assets

 

$

1,165

 

Goodwill(1)

 

 

3,165

 

Intangible assets(2)

 

 

1,760

 

​  

​  

Total purchase price

 

$

6,090

 

​  

​  

​  

​  

The Company acquired a net deferred tax liability of $0.1 million in this business combination.

 

 

 

 


 

 

 

(1)          

Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible assets acquired and liabilities assumed. The goodwill in this transaction is primarily attributable to the future cash flows to be realized from the acquired technology platform, existing customer base and the future development initiatives of the assembled workforce. Goodwill is not deductible for tax purposes.

(2)          

Identifiable finite-lived intangible assets were comprised of the following:

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

1,300

 

3

Customer relationships

 

 

400

 

5

Trade name

 

 

60

 

2

​  

​  

Total intangible assets acquired

 

$

1,760

 

 

​  

​  

​  

​  

 

 

                                                                                                                                                                                    

 

 

Total

 

Estimated
life
(in years)

Developed technology

 

$

1,300

 

3

Customer relationships

 

 

400

 

5

Trade name

 

 

60

 

2

​  

​  

Total intangible assets acquired

 

$

1,760

 

 

​  

​  

​  

​  

 

Goodwill and Intangible Assets (Tables)

 

        Goodwill balance as of December 31, 2017 and 2016 was as follows (in thousands):

                                                                                                                                                                                                

 

 

Total

 

Balance as of December 31, 2015

 

$

3,165

 

Goodwill recorded in connection with 2016 acquisition

 

 

400

 

​  

​  

Balance as of December 31, 2016

 

 

3,565

 

Goodwill recorded in connection with 2017 acquisition

 

 

12,688

 

Measurement period adjustment

 

 

149

 

Effect of exchange rate

 

 

1,449

 

​  

​  

Balance as of December 31, 2017

 

$

17,851

 

​  

​  

​  

​  

 

 

        Intangible assets consisted of the following (in thousands):

                                                                                                                                                                                                

 

 

As of December 31, 2017

 

 

 

Gross

 

Accumulated
Amortization

 

Net

 

Amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Developed technology

 

$

14,941

 

$

(5,476

)

$

9,465

 

Customer relationships

 

 

7,159

 

 

(1,006

)

 

6,153

 

Supplier relationships

 

 

2,881

 

 

(500

)

 

2,381

 

Trade name

 

 

60

 

 

(60

)

 

 

Patent

 

 

1,878

 

 

(108

)

 

1,770

 

​  

​  

​  

​  

​  

​  

Total amortizable intangible assets

 

 

26,919

 

 

(7,150

)

 

19,769

 

​  

​  

​  

​  

​  

​  

Non-amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Domain names

 

 

32

 

 

 

 

32

 

Trademarks

 

 

263

 

 

 

 

263

 

​  

​  

​  

​  

​  

​  

Total

 

$

27,214

 

$

(7,150

)

$

20,064

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

                                                                                                                                                                                    

 

 

As of December 31, 2016

 

 

 

Gross

 

Accumulated
Amortization

 

Net

 

Amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Developed technology

 

$

9,400

 

$

(1,140

)

$

8,260

 

Customer relationships

 

 

400

 

 

(148

)

 

252

 

Trade name

 

 

60

 

 

(56

)

 

4

 

Patent

 

 

1,512

 

 

(55

)

 

1,457

 

​  

​  

​  

​  

​  

​  

Total amortizable intangible assets

 

 

11,372

 

 

(1,399

)

 

9,973

 

​  

​  

​  

​  

​  

​  

Non-amortizable intangible assets:

 

 

 

 

 

 

 

 

 

 

Domain names

 

 

32

 

 

 

 

32

 

Trademarks

 

 

263

 

 

 

 

263

 

​  

​  

​  

​  

​  

​  

Total

 

$

11,667

 

$

(1,399

)

$

10,268

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

        Total estimated future amortization expense was as follows (in thousands):

                                                                                                                                                                                                

 

 

As of
December 31,
2017

 

2018

 

$

6,793

 

2019

 

 

5,083

 

2020

 

 

2,653

 

2021

 

 

1,520

 

2022

 

 

924

 

Thereafter

 

 

2,796

 

​  

​  

Total

 

$

19,769

 

​  

​  

​  

​  

 

Accrued Expenses and Other Liabilities (Tables)

 

        Accrued expenses and other current liabilities consisted of the following (in thousands):

                                                                                                                                                                                                

 

 

As of
December 31,

 

 

 

2017

 

2016

 

Accrued payroll and related

 

$

4,898

 

$

3,132

 

Accrued bonus and commission

 

 

4,777

 

 

2,251

 

Accrued cost of revenue

 

 

10,876

 

 

8,741

 

Sales and other taxes payable

 

 

20,877

 

 

28,795

 

ESPP contributions

 

 

1,338

 

 

4,365

 

Deferred rent

 

 

1,048

 

 

1,250

 

Accrued other expense

 

 

9,800

 

 

10,774

 

​  

​  

​  

​  

Total accrued expenses and other current liabilities

 

$

53,614

 

$

59,308

 

​  

​  

​  

​  

​  

​  

​  

​  

 

 

        Long-term liabilities consisted of the following (in thousands):

                                                                                                                                                                                    

 

 

As of
December 31,

 

 

 

2017

 

2016

 

Deferred rent

 

$

8,480

 

$

9,387

 

Deferred tax liability

 

 

2,452

 

 

(2)

 

Accrued other expense

 

 

477

 

 

158

 

​  

​  

​  

​  

Total long-term liabilities

 

$

11,409

 

$

9,543

 

​  

​  

​  

​  

​  

​  

​  

​  

 

Supplemental Balance Sheet Information (Tables)

 

        A roll-forward of the Company's reserves for the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands):

 

 

 

           

(a)          

Allowance for doubtful accounts:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Balance, beginning of period

 

$

1,076

 

$

486

 

$

210

 

Additions

 

 

580

 

 

1,145

 

 

705

 

Write-offs

 

 

(623

)

 

(555

)

 

(429

)

​  

​  

​  

​  

​  

​  

Balance, end of period

 

$

1,033

 

$

1,076

 

$

486

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

        A roll-forward of the Company's reserves for the years ended December 31, 2017, 2016 and 2015 is as follows (in thousands):

 

 

 

           

(b)          

Sales credit reserve:

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Balance, beginning of period

 

$

544

 

$

714

 

$

312

 

Additions

 

 

2,531

 

 

1,348

 

 

1,210

 

Deductions against reserve

 

 

(1,314

)

 

(1,518

)

 

(808

)

​  

​  

​  

​  

​  

​  

Balance, end of period

 

$

1,761

 

$

544

 

$

714

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Revenue by Geographic Area (Tables)
Schedule of revenue by geographic area

 

The following table sets forth revenue by geographic area (in thousands):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Revenue by geographic area:

 

 

 

 

 

 

 

 

 

 

United States

 

$

308,612

 

$

233,922

 

$

143,145

 

International

 

 

90,408

 

 

43,413

 

 

23,774

 

​  

​  

​  

​  

​  

​  

Total

 

$

399,020

 

$

277,335

 

$

166,919

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Percentage of revenue by geographic area:

 

 

 

 

 

 

 

 

 

 

United States

 

 

77

%

 

84

%

 

86

%

International

 

 

23

%

 

16

%

 

14

%

 

Commitments and Contingencies (Tables)

 

        Future minimum lease payments under non-cancelable operating leases were as follows (in thousands):

                                                                                                                                                                                    

Year Ending December 31:

 

As of
December 31,
2017

 

2018

 

$

7,884

 

2019

 

 

7,676

 

2020

 

 

7,101

 

2021

 

 

7,033

 

2022

 

 

5,864

 

Thereafter

 

 

10,189

 

​  

​  

Total minimum lease payments

 

$

45,747

 

​  

​  

​  

​  

 

 

Future minimum payments under these noncancellable purchase commitments were as follows (in thousands).

                                                                                                                                                                                    

Year Ending December 31:

 

As of
December 31,
2017

 

2018

 

$

22,414

 

2019

 

 

25,526

 

2020

 

 

147

 

2021

 

 

23

 

​  

​  

Total payments

 

$

48,110

 

​  

​  

​  

​  

 

Stockholders' Equity (Tables)

 

        As of December 31, 2015, the Company had outstanding Series A, B, C, D, E and T convertible preferred stock (individually referred to as "Series A, B, C, D, E or T" or collectively "Preferred Stock") as follows (in thousands, except share data).

 

                                                                                                                                                                                    

 

 

As of December 31, 2015

 

 

 

Shares
Authorized

 

Shares Issued
and
Outstanding

 

Aggregate
Liquidation
preference

 

Proceeds, Net
of Issuance
Costs

 

Series A

 

 

13,173,240

 

 

13,076,491

 

$

4,590

 

$

4,592

 

Series B

 

 

11,416,062

 

 

11,146,895

 

 

11,717

 

 

11,658

 

Series C

 

 

8,452,864

 

 

8,452,864

 

 

25,250

 

 

25,196

 

Series D

 

 

9,440,324

 

 

9,440,324

 

 

70,000

 

 

69,930

 

Series E

 

 

11,494,249

 

 

11,494,249

 

 

130,000

 

 

125,448

 

Series T

 

 

5,000,000

 

 

897,618

(1)

 

9

 

 

(2)

​  

​  

​  

​  

​  

​  

​  

​  

Total

 

 

58,976,739

 

 

54,508,441

 

$

241,566

 

$

236,824

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  


 

 

 

(1)          

The outstanding shares include 687,885 shares held in escrow as of December 31, 2015 related to the Authy acquisition. Of these shares, 507,885 shares were subject to graded vesting over a period of three years, as amended, and had a fair value of $4.0 million. A total of 127,054 shares were subject to certain performance conditions and were returned to the issuer in the third quarter 2016 due to the non-fulfillment of certain conditions of the merger agreement. All remaining unvested shares vested in the fourth quarter of 2016.

(2)          

389,733 shares were issued as part of the purchase price for Authy acquisition and had a fair value of $3.1 million on the acquisition closing date.

 

                                                                                                                                                                                                

 

 

As of December 31,

 

 

 

2017

 

2016

 

Stock options issued and outstanding

 

 

10,710,427

 

 

14,649,276

 

Nonvested restricted stock units issued and outstanding

 

 

5,665,459

 

 

2,034,217

 

Class A common stock reserved for Twilio.org

 

 

635,014

 

 

680,397

 

Stock-based awards available for grant under 2016 Plan

 

 

10,200,189

 

 

10,143,743

 

Class A common stock reserved for issuance under 2016 ESPP

 

 

235,372

 

 

597,038

 

​  

​  

​  

​  

Total

 

 

27,446,461

 

 

28,104,671

 

​  

​  

​  

​  

 

Stock-Based Compensation (Tables)

 

                                                                                                                                                                                                 

 

 

Number of
options
outstanding

 

Weighted-
average
exercise
price
(per share)

 

Weighted-
average
remaining
contractual
term
(in years)

 

Aggregate
intrinsic
value
(in thousands)

 

Outstanding options as of December 31, 2016

 

 

14,649,276

 

$

6.14

 

 

7.52

 

$

332,716

 

Granted

 

 

1,526,450

 

 

30.66

 

 

 

 

 

 

 

Exercised

 

 

(5,194,905

)

 

4.93

 

 

 

 

 

 

 

Forfeited and cancelled

 

 

(825,394

)

 

7.76

 

 

 

 

 

 

 

​  

​  

Outstanding options as of December 31, 2017

 

 

10,155,427

 

$

10.31

 

 

7.12

 

$

145,763

 

​  

​  

​  

​  

Options vested and exercisable as of December 31, 2017

 

 

5,278,003

 

$

5.53

 

 

6.28

 

$

95,354

 

​  

​  

​  

​  

 

 

                                                                                                                                                                                                 

 

 

Number of
options
outstanding

 

Weighted-
average
grant date
fair value
(per share)

 

Aggregate
intrinsic
value
(in thousands)

 

Nonvested RSUs as of December 31, 2016

 

 

2,034,217

 

$

32.66

 

$

58,687

 

Granted

 

 

4,826,508

 

 

28.05

 

 

 

 

Vested

 

 

(711,371

)

 

30.29

 

 

 

 

Forfeited and cancelled

 

 

(483,895

)

 

29.53

 

 

 

 

​  

​  

Nonvested RSUs as of December 31, 2017

 

 

5,665,459

 

$

29.29

 

$

133,648

 

​  

​  

​  

​  

 

 

                                                                                                                                                                                                

 

 

Year Ended December 31,

 

 

2017

 

2016

 

2015

Employee Stock Purchase Plan

 

 

 

 

 

 

Expected term (in years)

 

0.5

 

0.90

 

Expected volatility

 

33.2% - 33.9%

 

52%

 

Risk-free interest rate

 

1.1% - 1.4%

 

0.6%

 

Dividend rate

 

0%

 

0%

 

 

 

        The Company recorded the total stock-based compensation expense as follows (in thousands):

                                                                                                                                                                                                

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Cost of revenue

 

$

650

 

$

291

 

$

65

 

Research and development

 

 

22,808

 

 

12,946

 

 

4,046

 

Sales and marketing

 

 

9,822

 

 

4,972

 

 

2,389

 

General and administrative

 

 

16,339

 

 

6,016

 

 

2,377

 

​  

​  

​  

​  

​  

​  

Total

 

$

49,619

 

$

24,225

 

$

8,877

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

                                                                                                                                                                                                 

 

 

Year Ended December 31,

 

 

2017

 

2016

 

2015

Employee Stock Options

 

 

 

 

 

 

Fair value of common stock

 

$23.60 - $31.96

 

$10.09 - $15.00

 

$7.07 - $10.09

Expected term (in years)

 

6.08

 

6.08

 

6.08

Expected volatility

 

44.3% - 47.6%

 

51.4% - 53.0%

 

47.8% - 54.9%

Risk-free interest rate

 

1.9% - 2.3%

 

1.3% - 1.5%

 

1.4% - 2.0%

Dividend rate

 

0%

 

0%

 

0%

 

 

                                                                                                                                                                                                 

 

 

Number of
options
outstanding

 

Weighted-
average
exercise
price
(per share)

 

Weighted-
average
remaining
contractual
term
(in years)

 

Aggregate
intrinsic
value
(in thousands)

 

Outstanding options as of December 31, 2016

 

 

 

$

 

 

 

$

 

Granted

 

 

555,000

 

 

31.72

 

 

 

 

 

 

 

Exercised

 

 

 

 

 

 

 

 

 

 

 

Forfeited and cancelled

 

 

 

 

 

 

 

 

 

 

 

​  

​  

Outstanding options as of December 31, 2017

 

 

555,000

 

$

31.72

 

 

6.0

 

$

 

​  

​  

​  

​  

Options vested and exercisable as of December 30, 2017

 

 

 

$

 

 

 

$

 

​  

​  

​  

​  

 

 

                                                                                                                                                                                                 

Asset volatility

 

 

40

%

Equity volatility

 

 

45

%

Discount rate

 

 

14

%

Stock price at grant date

 

$

31.72

 

 

Net Loss Per Share Attributable to Common Stockholders (Tables)

 

        The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented (in thousands, except per share data):

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Net loss attributable to common stockholders

 

$

(63,708

)

$

(41,324

)

$

(38,896

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted

 

 

91,224,607

 

 

53,116,675

 

 

17,746,526

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

Net loss per share attributable to common stockholders, basic and diluted

 

$

(0.70

)

$

(0.78

)

$

(2.19

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

                                                                                                                                                                                    

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Convertible preferred stock outstanding

 

 

 

 

 

 

54,508,441

(1)

Stock options issued and outstanding

 

 

10,710,427

 

 

14,649,276

 

 

16,883,837

 

Nonvested restricted stock units issued and outstanding

 

 

5,665,459

 

 

2,034,217

 

 

71,000

 

Class A common stock reserved for Twilio.org

 

 

635,014

 

 

680,397

 

 

888,022

 

Class A common stock committed under 2016 ESPP

 

 

235,372

 

 

597,038

 

 

 

Unvested shares subject to repurchase

 

 

5,214

 

 

49,580

 

 

52,407

 

​  

​  

​  

​  

​  

​  

Total

 

 

17,251,486

 

 

18,010,508

 

 

72,403,707

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  


 

 

 

(1)          

Includes 687,885 shares as of December 31, 2015 of Series T convertible preferred stock related to the Authy acquisition held in escrow.

 

Income Taxes (Tables)

        The following table presents domestic and foreign components of loss before income taxes for the periods presented (in thousands):

                                                                                                                                                                                                 

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

United States

 

$

(46,737

)

$

(14,002

)

$

(23,962

)

International

 

 

(16,266

)

 

(26,996

)

 

(11,420

)

​  

​  

​  

​  

​  

​  

Loss before provision for income taxes

 

$

(63,003

)

$

(40,998

)

$

(35,382

)

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

        Provision for income taxes consists of the following (in thousands):

                                                                                                                                                                                                 

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Current:

 

 

 

 

 

 

 

 

 

 

Federal

 

$

99

 

$

 

$

 

State

 

 

78

 

 

83

 

 

45

 

Foreign

 

 

823

 

 

214

 

 

213

 

​  

​  

​  

​  

​  

​  

Total

 

 

1,000

 

 

297

 

 

258

 

Deferred:

 

 

 

 

 

 

 

 

 

 

Federal

 

 

28

 

 

2

 

 

(109

)

State

 

 

10

 

 

 

 

 

Foreign

 

 

(333

)

 

27

 

 

(27

)

​  

​  

​  

​  

​  

​  

Total

 

 

(295

)

 

29

 

 

(136

)

​  

​  

​  

​  

​  

​  

Provision for income taxes

 

$

705

 

$

326

 

$

122

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

                                                                                                                                                                                                

 

 

Year Ended
December 31,

 

 

 

2017

 

2016

 

2015

 

Tax benefit at federal statutory rate

 

 

34

%

 

34

%

 

34

%

State tax, net of federal benefit

 

 

10

 

 

11

 

 

(3

)

Stock-based compensation

 

 

47

 

 

23

 

 

(8

)

Credits

 

 

8

 

 

2

 

 

4

 

Foreign rate differential

 

 

(8

)

 

(23

)

 

(11

)

Reserve for uncertain tax positions

 

 

 

 

(12

)

 

 

Change in valuation allowance

 

 

(46

)

 

(34

)

 

(14

)

Change in federal statutory rate

 

 

(45

)

 

 

 

 

Other

 

 

(1

)

 

(2

)

 

(2

)

​  

​  

​  

​  

​  

​  

Effective tax rate

 

 

(1

)%

 

(1

)%

 

%

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

 

The following table presents the significant components of the Company's deferred tax assets and liabilities (in thousands):

                                                                                                                                                                                    

 

 

As of December 31,

 

 

 

2017

 

2016

 

2015

 

Deferred tax assets:

 

 

 

 

 

 

 

 

 

 

Net operating loss carryforwards

 

$

56,138

 

$

31,090

 

$

27,401

 

Accrued and prepaid expenses

 

 

9,140

 

 

16,698

 

 

7,603

 

Stock-based compensation

 

 

7,131

 

 

5,368

 

 

1,433

 

Research and development credits

 

 

16,212

 

 

7,807

 

 

6,022

 

Charitable contributions

 

 

1,233

 

 

1,458

 

 

 

Other

 

 

472

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gross deferred tax assets

 

 

90,326

 

 

62,421

 

 

42,459

 

Valuation allowance

 

 

(78,900

)

 

(49,601

)

 

(35,613

)

 

 

 

 

 

 

 

 

 

 

 

Net deferred tax assets

 

 

11,426

 

 

12,820

 

 

6,846

 

Deferred tax liabilities:

 

 

 

 

 

 

 

 

 

 

Capitalized software

 

 

(7,664

)

 

(7,086

)

 

(4,084

)

Prepaid expenses

 

 

(1,015

)

 

(452

)

 

(2,035

)

Acquired intangibles

 

 

(2,101

)

 

(152

)

 

(460

)

Property and equipment

 

 

(2,380

)

 

(4,931

)

 

(240

)

Deferred commissions

 

 

(718

)

 

(201

)

 

 

 

 

 

 

 

 

 

 

 

 

 

Net deferred tax asset (liability)

 

$

(2,452

)

$

(2

)

$

27

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

        A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

                                                                                                                                                                                                

 

 

Year Ended December 31,

 

 

 

2017

 

2016

 

2015

 

Unrecognized tax benefit, beginning of year

 

$

12,275

 

$

1,679

 

$

1,024

 

Gross increases for tax positions of prior years

 

 

493

 

 

1,996

 

 

 

Gross decrease for tax positions of prior years

 

 

(6,331

)

 

 

 

 

Gross increases for tax positions of current years

 

 

3,008

 

 

8,600

 

 

655

 

​  

​  

​  

​  

​  

​  

Unrecognized tax benefit, end of year

 

$

9,445

 

$

12,275

 

$

1,679

 

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

​  

 

Organization and Description of Business - Initial Public Offering (Details) (USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended
Jun. 30, 2016
Common Class B
 
Initial Public Offering
 
Shares issued upon automatic conversion (in shares)
54,508,441 
Conversion ratio
IPO |
Common Class A
 
Initial Public Offering
 
Shares sold (in shares)
11,500,000 
Stock price at grant date (in dollars per share)
$ 15.00 
Proceeds received, after deducting underwriting discounts and offering expenses
$ 155.5 
Over-Allotment Option, IPO |
Common Class A
 
Initial Public Offering
 
Shares sold (in shares)
1,500,000 
Organization and Description of Business - Follow-on Public Offering (Details) (Common Class A, USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended
Oct. 31, 2016
Follow-on Public Offering
 
Follow-on Public Offering
 
Shares sold (in shares)
1,691,222 
Stock price at grant date (in dollars per share)
$ 40.00 
Proceeds received, after deducting underwriting discounts and offering expenses
$ 64.4 
Over-Allotment Option, FPO
 
Follow-on Public Offering
 
Shares sold (in shares)
1,050,000 
Stock Sold by Certain Selling Stockholders
 
Follow-on Public Offering
 
Shares sold (in shares)
6,358,778 
Stock option exercises (in shares)
906,364 
Summary of Significant Accounting Policies - Concentration of Credit Risk (Details)
12 Months Ended
Dec. 31, 2017
customer
Dec. 31, 2016
customer
Dec. 31, 2015
customer
Revenue |
Customer Concentration Risk
 
 
 
Concentration of Credit Risk
 
 
 
Number of customers
Revenue |
Customer Concentration Risk |
Customer One
 
 
 
Concentration of Credit Risk
 
 
 
Concentration risk (as a percent)
 
14.00% 
 
Revenue |
Customer Concentration Risk |
Customer Two
 
 
 
Concentration of Credit Risk
 
 
 
Concentration risk (as a percent)
 
 
17.00% 
Accounts Receivable |
Credit Concentration Risk
 
 
 
Concentration of Credit Risk
 
 
 
Number of customers
 
Accounts Receivable |
Credit Concentration Risk |
Customer One
 
 
 
Concentration of Credit Risk
 
 
 
Concentration risk (as a percent)
 
16.00% 
 
Summary of Significant Accounting Policies - Revenue Recognition (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Minimum
Dec. 31, 2017
Maximum
Dec. 31, 2017
Sales credit reserve
Dec. 31, 2016
Sales credit reserve
Dec. 31, 2015
Sales credit reserve
Dec. 31, 2014
Sales credit reserve
Revenue Recognition
 
 
 
 
 
 
Reserve for sales credits
 
 
$ 1,761 
$ 544 
$ 714 
$ 312 
Duration of contracts
1 month 
48 months 
 
 
 
 
Summary of Significant Accounting Policies - Internal-Use Software Development Costs (Details) (Capitalized internal-use software development costs)
12 Months Ended
Dec. 31, 2017
Capitalized internal-use software development costs
 
Internal-Use Software Development Costs
 
Estimated useful life (in years)
3 years 
Summary of Significant Accounting Policies - Advertising Costs (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Summary of Significant Accounting Policies
 
 
 
Advertising expense
$ 4.9 
$ 3.5 
$ 2.9 
Summary of Significant Accounting Policies - Stock-Based Compensation (Details) (USD $)
12 Months Ended 3 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Accounting Standards Update 2016-09
Early Adoption Impact
Stock-Based Compensation
 
 
Increase in stock-based compensation expense for cumulative prior year impact
 
$ 100,000 
Increase in stock-based compensation expense for 2016 quarterly impact
 
$ 75,000 
Expected dividend rate for Black-Scholes model (as a percent)
0.00% 
 
Summary of Significant Accounting Policies - Net Loss Per Share Attributable to Common Stockholders (Details)
12 Months Ended
Dec. 31, 2017
Vote
Common Class A
 
Net Loss Per Share Attributable to Common Stockholders
 
Votes per share
Common Class B
 
Net Loss Per Share Attributable to Common Stockholders
 
Votes per share
10 
Ratio for option to convert to Class A
Summary of Significant Accounting Policies - Restricted Cash (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Summary of Significant Accounting Policies
 
 
Restricted cash balances
$ 5.5 
$ 8.6 
Summary of Significant Accounting Policies - Accounts Receivable and Allowance for Doubtful Accounts (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Summary of Significant Accounting Policies
 
 
 
 
Allowance for doubtful accounts
$ 1,033 
$ 1,076 
$ 486 
$ 210 
Summary of Significant Accounting Policies - Property and Equipment (Details)
12 Months Ended
Dec. 31, 2017
Capitalized internal-use software development costs
 
Property and Equipment
 
Estimated useful life (in years)
3 years 
Office equipment
 
Property and Equipment
 
Estimated useful life (in years)
3 years 
Furniture and fixtures
 
Property and Equipment
 
Estimated useful life (in years)
5 years 
Software
 
Property and Equipment
 
Estimated useful life (in years)
3 years 
Leasehold improvements
 
Property and Equipment
 
Estimated useful life (in years)
5 years 
Summary of Significant Accounting Policies - Intangible Assets (Details)
12 Months Ended
Dec. 31, 2017
Developed technology |
Minimum
 
Intangible Assets
 
Useful life (in years)
3 years 
Developed technology |
Maximum
 
Intangible Assets
 
Useful life (in years)
4 years 
Customer relationships |
Minimum
 
Intangible Assets
 
Useful life (in years)
5 years 
Customer relationships |
Maximum
 
Intangible Assets
 
Useful life (in years)
8 years 
Supplier relationships
 
Intangible Assets
 
Useful life (in years)
5 years 
Trade name
 
Intangible Assets
 
Useful life (in years)
2 years 
Patent
 
Intangible Assets
 
Useful life (in years)
20 years 
Summary of Significant Accounting Policies - Goodwill (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
item
Dec. 31, 2016
Dec. 31, 2015
Summary of Significant Accounting Policies
 
 
 
Number of reporting units
 
 
Goodwill impairment charges
$ 0 
$ 0 
$ 0 
Summary of Significant Accounting Policies - Impairment of Long Lived Assets (Details) (USD $)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Summary of Significant Accounting Policies
 
 
 
Long-lived assets, including property and equipment and intangible assets, impairment loss
$ 0 
$ 0 
$ 0 
Value of internally-developed software written-off due to abandonment
$ 561,000 
$ 711,000 
$ 113,000 
Summary of Significant Accounting Policies - Segment Information (Details)
12 Months Ended
Dec. 31, 2017
segment
Summary of Significant Accounting Policies
 
Number of reportable segments
Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2017
Recurring
Dec. 31, 2017
Recurring
U.S. Treasury securities
Dec. 31, 2017
Recurring
Corporate debt securities
Dec. 31, 2017
Recurring
Carrying Value
Dec. 31, 2016
Recurring
Carrying Value
Dec. 31, 2017
Recurring
Carrying Value
Money market funds
Dec. 31, 2016
Recurring
Carrying Value
Money market funds
Dec. 31, 2017
Recurring
Aggregate Fair Value
Dec. 31, 2016
Recurring
Aggregate Fair Value
Dec. 31, 2017
Recurring
Aggregate Fair Value
U.S. Treasury securities
Dec. 31, 2017
Recurring
Aggregate Fair Value
Corporate debt securities
Dec. 31, 2017
Recurring
Aggregate Fair Value
Money market funds
Dec. 31, 2016
Recurring
Aggregate Fair Value
Money market funds
Dec. 31, 2017
Recurring
Aggregate Fair Value
Level 1
Dec. 31, 2016
Recurring
Aggregate Fair Value
Level 1
Dec. 31, 2017
Recurring
Aggregate Fair Value
Level 1
U.S. Treasury securities
Dec. 31, 2017
Recurring
Aggregate Fair Value
Level 1
Money market funds
Dec. 31, 2016
Recurring
Aggregate Fair Value
Level 1
Money market funds
Dec. 31, 2017
Recurring
Aggregate Fair Value
Level 2
Dec. 31, 2017
Recurring
Aggregate Fair Value
Level 2
Corporate debt securities
Fair Value Measurements
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cash and cash equivalents
 
 
 
 
 
$ 95,432 
 
$ 95,432 
$ 274,135 
$ 95,432 
 
 
 
$ 95,432 
$ 274,135 
$ 95,432 
 
 
$ 95,432 
$ 274,135 
 
 
Marketable securities, Amortized Cost
176,185 
 
176,185 
59,962 
116,223 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Marketable securities, Net Unrealized Losses
 
 
(598)
(216)
(382)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Total marketable securities, Aggregate Fair Value
175,587 
 
 
 
 
 
 
 
175,587 
 
59,746 
115,841 
 
 
59,746 
 
59,746 
 
 
115,841 
115,841 
Total financial assets, Amortized Cost or Carrying Value
 
 
271,617 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Total financial assets
 
 
 
 
 
 
$ 274,135 
 
 
$ 271,019 
$ 274,135 
 
 
 
 
$ 155,178 
$ 274,135 
 
 
 
$ 115,841 
 
Fair Value Measurements - Contractual Maturities (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Fair Value Measurements
 
 
Less than one year, Amortized Cost
$ 108,584 
 
One to two years, Amortized Cost
67,601 
 
Total amortized cost
176,185 
 
Less than one year, Aggregate Fair Value
108,360 
 
One to two years, Aggregate Fair Value
67,227 
 
Total marketable securities, Aggregate Fair Value
$ 175,587 
$ 0 
Fair Value Measurements - Additional Disclosures (Details) (USD $)
12 Months Ended
Dec. 31, 2017
Fair Value Measurements
 
Other-than-temporary impairments
$ 0 
Interest earned on marketable securities
$ 2,600,000 
Property and Equipment - Property and Equipment, Net (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Property and Equipment
 
 
Total property and equipment
$ 76,726 
$ 50,997 
Less: accumulated depreciation and amortization
(26,185)
(13,445)
Total property and equipment, net
50,541 
37,552 
Capitalized internal-use software development costs
 
 
Property and Equipment
 
 
Total property and equipment
49,177 
28,661 
Leasehold improvements
 
 
Property and Equipment
 
 
Total property and equipment
14,246 
14,063 
Office equipment
 
 
Property and Equipment
 
 
Total property and equipment
9,652 
5,729 
Furniture and fixtures
 
 
Property and Equipment
 
 
Total property and equipment
1,976 
1,576 
Software
 
 
Property and Equipment
 
 
Total property and equipment
$ 1,675 
$ 968 
Property and Equipment - Depreciation and Amortization Expense (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property and Equipment
 
 
 
Depreciation and amortization
$ 13.1 
$ 7.4 
$ 3.7 
Property and Equipment - Capitalized Stock-Based Compensation Expense (Details) (USD $)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property and Equipment
 
 
 
Capitalized software development costs
$ 21,500,000 
$ 13,500,000 
$ 9,400,000 
Stock-based compensation capitalized in software development costs
$ 4,176,000 
$ 1,953,000 
$ 979,000 
Property and Equipment - Amortization of Capitalized Software Development Costs (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property and Equipment
 
 
 
Capitalized software amortization expense
$ 8,407 
$ 5,486 
$ 2,838 
Cost of revenue
 
 
 
Property and Equipment
 
 
 
Capitalized software amortization expense
4,788 
3,304 
1,793 
Research and development
 
 
 
Property and Equipment
 
 
 
Capitalized software amortization expense
$ 3,619 
$ 2,182 
$ 1,045 
Business Combinations - Consideration (Details) (USD $)
In Millions, unless otherwise specified
1 Months Ended 10 Months Ended 1 Months Ended 12 Months Ended
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Dec. 31, 2017
Beepsend AB, a messaging provider based in Sweden
Nov. 30, 2016
Kurento Open Source Project
Feb. 28, 2015
Authy, Inc.
Dec. 31, 2015
Authy, Inc.
Acquisition
 
 
 
 
 
Total purchase price
$ 23.0 
 
$ 8.5 
$ 6.1 
 
Purchase price paid in cash
23.0 
 
8.5 
3.0 
 
Purchase price, fair value of shares of Series T convertible preferred stock
 
 
 
3.1 
3.1 
Amount of purchase price placed into an escrow account
5.0 
 
1.5 
 
 
Escrow effective period
18 months 
 
24 months 10 days 
 
 
Amount deposited into an employee escrow account
2.0 
 
 
 
 
Adjustment to preliminary purchase price allocation
 
$ 0.1 
 
 
 
Business Combinations - Purchase Price Allocation (Details) (USD $)
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Feb. 28, 2015
Authy, Inc.
Nov. 30, 2016
Kurento Open Source Project
Acquisition
 
 
 
 
 
 
Net tangible assets
 
 
 
 
$ 1,165,000 
 
Net tangible liabilities
 
 
 
(3,575,000)
 
 
Goodwill
17,851,000 
3,565,000 
3,165,000 
12,837,000 
3,165,000 
400,000 
Intangible assets
 
 
 
13,700,000 
1,760,000 
8,100,000 
Total purchase price
 
 
 
22,962,000 
6,090,000 
8,500,000 
Net deferred tax liability
 
 
 
$ 2,600,000 
$ 100,000 
 
Business Combinations - Identifiable Finite-lived Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended 1 Months Ended 1 Months Ended 1 Months Ended 1 Months Ended
Dec. 31, 2017
Developed technology
Minimum
Dec. 31, 2017
Developed technology
Maximum
Dec. 31, 2017
Customer relationships
Minimum
Dec. 31, 2017
Customer relationships
Maximum
Dec. 31, 2017
Supplier relationships
Dec. 31, 2017
Trade name
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Developed technology
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Customer relationships
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Customer relationships
Minimum
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Customer relationships
Maximum
Feb. 28, 2017
Beepsend AB, a messaging provider based in Sweden
Supplier relationships
Feb. 28, 2015
Authy, Inc.
Feb. 28, 2015
Authy, Inc.
Developed technology
Feb. 28, 2015
Authy, Inc.
Customer relationships
Feb. 28, 2015
Authy, Inc.
Trade name
Nov. 30, 2016
Kurento Open Source Project
Nov. 30, 2016
Kurento Open Source Project
Developed technology
Acquisition
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Total intangible assets acquired
 
 
 
 
 
 
$ 13,700 
$ 5,000 
$ 6,100 
 
 
$ 2,600 
$ 1,760 
$ 1,300 
$ 400 
$ 60 
$ 8,100 
 
Estimated life (in years)
3 years 
4 years 
5 years 
8 years 
5 years 
2 years 
 
4 years 
 
7 years 
8 years 
5 years 
 
3 years 
5 years 
2 years 
 
3 years 
Business Combinations - Acquisition Costs (Details) (General and administrative, USD $)
In Millions, unless otherwise specified
12 Months Ended 24 Months Ended 12 Months Ended 24 Months Ended 12 Months Ended
Dec. 31, 2017
Beepsend AB, a messaging provider based in Sweden
Dec. 31, 2016
Beepsend AB, a messaging provider based in Sweden
Dec. 31, 2017
Beepsend AB, a messaging provider based in Sweden
Dec. 31, 2015
Authy, Inc.
Dec. 31, 2014
Authy, Inc.
Dec. 31, 2015
Authy, Inc.
Dec. 31, 2016
Kurento Open Source Project
Business Combinations
 
 
 
 
 
 
 
Acquisition related costs
$ 0.3 
$ 0.4 
$ 0.7 
$ 1.2 
$ 0.3 
$ 1.5 
$ 0.1 
Business Combinations - Consideration - Shares of Stock (Details) (Authy, Inc., Preferred Stock, Series T Preferred Stock, USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended 12 Months Ended
Feb. 28, 2015
Dec. 31, 2015
Aug. 31, 2016
Acquisition
 
 
 
Shares issued (in shares)
389,733 
389,733 
 
Shares held in escrow (in shares)
180,000 
687,885 
 
Former Shareholder of Acquiree
 
 
 
Acquisition
 
 
 
Shares issued to former shareholder (in shares)
507,885 
507,885 
 
Fair value
$ 4.0 
$ 4.0 
 
Graded vesting period (in years)
3 years 
3 years 
 
Reduction in unvested shares due to non-fulfillment of certain conditions of the merger agreement (in shares)
 
 
127,054 
Business Combinations - Cost of Shares Subject to Vesting and Performance Conditions (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Business Combinations
 
 
 
Stock-based compensation expense
$ 49,619 
$ 24,225 
$ 8,877 
Research and development
 
 
 
Business Combinations
 
 
 
Stock-based compensation expense
22,808 
12,946 
4,046 
Research and development |
Authy, Inc.
 
 
 
Business Combinations
 
 
 
Stock-based compensation expense
 
$ 2,400 
$ 600 
Goodwill and Intangible Assets - Goodwill (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Goodwill
 
 
Balance at the beginning of the period
$ 3,565 
$ 3,165 
Goodwill recorded in connection with acquisitions
12,688 
400 
Measurement period adjustment
149 
 
Effect of exchange rate
1,449 
 
Balance at the end of the period
$ 17,851 
$ 3,565 
Goodwill and Intangible Assets - Amortizable Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Intangible Assets
 
 
Gross
$ 26,919 
$ 11,372 
Accumulated Amortization
(7,150)
(1,399)
Net
19,769 
9,973 
Developed technology
 
 
Intangible Assets
 
 
Gross
14,941 
9,400 
Accumulated Amortization
(5,476)
(1,140)
Net
9,465 
8,260 
Customer relationships
 
 
Intangible Assets
 
 
Gross
7,159 
400 
Accumulated Amortization
(1,006)
(148)
Net
6,153 
252 
Supplier relationships
 
 
Intangible Assets
 
 
Gross
2,881 
 
Accumulated Amortization
(500)
 
Net
2,381 
 
Trade name
 
 
Intangible Assets
 
 
Gross
60 
60 
Accumulated Amortization
(60)
(56)
Net
 
Patent
 
 
Intangible Assets
 
 
Gross
1,878 
1,512 
Accumulated Amortization
(108)
(55)
Net
$ 1,770 
$ 1,457 
Goodwill and Intangible Assets - Non-amortizable Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Domain names
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
$ 32 
$ 32 
Trademarks
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
$ 263 
$ 263 
Goodwill and Intangible Assets - Total Intangible Assets, Gross (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Intangible Assets
 
 
Amortizable intangible assets, gross
$ 26,919 
$ 11,372 
Total
27,214 
11,667 
Domain names
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
32 
32 
Trademarks
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
$ 263 
$ 263 
Goodwill and Intangible Assets - Total Intangible Assets, Net (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Intangible Assets
 
 
Amortizable intangible assets, net
$ 19,769 
$ 9,973 
Total
20,064 
10,268 
Domain names
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
32 
32 
Trademarks
 
 
Intangible Assets
 
 
Non-amortizable intangible assets
$ 263 
$ 263 
Goodwill and Intangible Assets - Total Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Goodwill and Intangible Assets
 
 
Gross
$ 27,214 
$ 11,667 
Accumulated Amortization
(7,150)
(1,399)
Net
$ 20,064 
$ 10,268 
Goodwill and Intangible Assets - Amortization Expense (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Goodwill and Intangible Assets
 
 
 
Amortization expense
$ 5.7 
$ 0.9 
$ 0.5 
Goodwill and Intangible Assets - Total Estimated Future Amortization Expense (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Intangible Assets
 
 
2018
$ 6,793 
 
2019
5,083 
 
2020
2,653 
 
2021
1,520 
 
2022
924 
 
Thereafter
2,796 
 
Net
$ 19,769 
$ 9,973 
Accrued Expenses and Other Liabilities - Accrued Expenses and Other Current Liabilities (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Accrued Expenses and Other Liabilities
 
 
Accrued payroll and related
$ 4,898 
$ 3,132 
Accrued bonus and commission
4,777 
2,251 
Accrued cost of revenue
10,876 
8,741 
Sales and other taxes payable
20,877 
28,795 
ESPP contributions
1,338 
4,365 
Deferred rent
1,048 
1,250 
Accrued other expense
9,800 
10,774 
Total accrued expenses and other current liabilities
$ 53,614 
$ 59,308 
Accrued Expenses and Other Liabilities - Long-term Liabilities (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Accrued Expenses and Other Liabilities
 
 
Deferred rent
$ 8,480 
$ 9,387 
Deferred tax liability
2,452 
 
Deferred tax benefit
 
(2)
Accrued other expense
477 
158 
Total long-term liabilities
$ 11,409 
$ 9,543 
Supplemental Balance Sheet Information - Allowance for Doubtful Accounts (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Allowance for doubtful accounts
 
 
 
Balance, beginning of period
$ 1,076 
$ 486 
$ 210 
Additions
580 
1,145 
705 
Write-offs
(623)
(555)
(429)
Balance, end of period
$ 1,033 
$ 1,076 
$ 486 
Supplemental Balance Sheet Information - Sales Credit Reserve (Details) (Sales credit reserve, USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Sales credit reserve
 
 
 
Sales credit reserve
 
 
 
Balance, beginning of period
$ 544 
$ 714 
$ 312 
Additions
2,531 
1,348 
1,210 
Deductions against reserve
(1,314)
(1,518)
(808)
Balance, end of period
$ 1,761 
$ 544 
$ 714 
Revenue by Geographic Area - Revenue by Geographic Area (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Revenue by geographic area
 
 
 
Revenue
$ 399,020 
$ 277,335 
$ 166,919 
United States
 
 
 
Revenue by geographic area
 
 
 
Revenue
308,612 
233,922 
143,145 
International
 
 
 
Revenue by geographic area
 
 
 
Revenue
$ 90,408 
$ 43,413 
$ 23,774 
Revenue by Geographic Area - Percentage of Revenue by Geographic Area (Details) (Revenue, Geographic Concentration Risk)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
United States
 
 
 
Percentage of revenue by geographic area
 
 
 
Percentage of revenue (as a percent)
77.00% 
84.00% 
86.00% 
International
 
 
 
Percentage of revenue by geographic area
 
 
 
Percentage of revenue (as a percent)
23.00% 
16.00% 
14.00% 
Commitments and Contingencies - Lease Commitments (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended 1 Months Ended 23 Months Ended
Dec. 31, 2017
Various Facilities Leases
Maximum
Oct. 31, 2016
Office Space, 375 Beale Street, San Francisco, California
Dec. 31, 2017
Office Space, 375 Beale Street, San Francisco, California
Jan. 31, 2016
Office Space, 375 Beale Street, San Francisco, California
sqft
Dec. 31, 2017
Office Space, 375 Beale Street, San Francisco, California
Letter of Credit
Dec. 31, 2016
Office Space, 375 Beale Street, San Francisco, California
Letter of Credit
Lease Commitments
 
 
 
 
 
 
Non-cancelable operating lease agreements, facilities, remaining term (in years)
6 years 
 
 
 
 
 
Area of office space (in square feet)
 
 
 
90,000 
 
 
Lease agreements term
 
96 months 
 
 
 
 
Monthly payment, first 60 months
 
$ 0.4 
 
 
 
 
Monthly payment, after 60 months
 
0.5 
 
 
 
 
Tenant improvements allowance
 
 
 
8.3 
 
 
Tenant improvement allowance collected
 
 
8.3 
 
 
 
Letter of credit
 
 
 
 
$ 5.5 
$ 7.4 
Commitments and Contingencies - Rent Expense (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Commitments and Contingencies
 
 
 
Rent expense
$ 8.1 
$ 7.3 
$ 4.1 
Commitments and Contingencies - Future Minimum Lease Payments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Future minimum lease payments
 
2018
$ 7,884 
2019
7,676 
2020
7,101 
2021
7,033 
2022
5,864 
Thereafter
10,189 
Total minimum lease payments
$ 45,747 
Commitments and Contingencies - Other Commitments (Details)
12 Months Ended
Dec. 31, 2017
Minimum
 
Non-cancelable contractual commitments
 
Expiration period (in years)
1 year 
Maximum
 
Non-cancelable contractual commitments
 
Expiration period (in years)
4 years 
Commitments and Contingencies - Future Minimum Payments under Other Existing Noncancellable Purchase Commitments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Future minimum payments under other existing noncancelable purchase commitments
 
2018
$ 22,414 
2019
25,526 
2020
147 
2021
23 
Total payments
$ 48,110 
Commitments and Contingencies - Indemnification Agreements (Details) (Indemnification Agreement, USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Indemnification Agreement
 
 
Indemnification Agreements
 
 
Amount accrued
$ 0 
$ 0 
Commitments and Contingencies - Other taxes (Details) (USD $)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Other taxes
 
 
 
Liability for uncertain tax positions
$ 20,900,000 
$ 28,800,000 
 
Net loss attributable to common stockholders
(63,708,000)
(41,324,000)
(38,896,000)
Change in estimate for non-income-based tax exposure - revisions in key assumptions
 
 
 
Other taxes
 
 
 
Net loss attributable to common stockholders
$ 13,400,000 
 
 
Stockholders' Equity - Convertible Preferred Stock - IPO (Details) (Common Class B)
1 Months Ended
Jun. 30, 2016
Common Class B
 
Convertible Preferred Stock
 
Shares issued upon automatic conversion (in shares)
54,508,441 
Conversion ratio
Stockholders' Equity - Convertible Preferred Stock - Tabular Disclosure (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Convertible preferred stock
Dec. 31, 2015
Series A Preferred Stock
Dec. 31, 2015
Series B Preferred Stock
Dec. 31, 2015
Series C Preferred Stock
Dec. 31, 2015
Series D Preferred Stock
Dec. 31, 2015
Series E Preferred Stock
Dec. 31, 2015
Series T Preferred Stock
Preferred Stock
 
 
 
 
 
 
 
 
 
Shares Authorized (in shares)
100,000,000 
100,000,000 
58,976,739 
13,173,240 
11,416,062 
8,452,864 
9,440,324 
11,494,249 
5,000,000 
Shares Issued (in shares)
54,508,441 
13,076,491 
11,146,895 
8,452,864 
9,440,324 
11,494,249 
897,618 
Shares Outstanding (in shares)
54,508,441 
13,076,491 
11,146,895 
8,452,864 
9,440,324 
11,494,249 
897,618 
Aggregate Liquidation preference
 
 
$ 241,566 
$ 4,590 
$ 11,717 
$ 25,250 
$ 70,000 
$ 130,000 
$ 9 
Proceeds, Net of Issuance Costs
 
 
$ 236,824 
$ 4,592 
$ 11,658 
$ 25,196 
$ 69,930 
$ 125,448 
 
Stockholders' Equity - Convertible Preferred Stock - Authy Acquisition (Details) (Authy, Inc., USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended 12 Months Ended
Feb. 28, 2015
Dec. 31, 2015
Acquisition
 
 
Purchase price, fair value of shares of Series T convertible preferred stock
$ 3.1 
$ 3.1 
Preferred Stock |
Series T Preferred Stock
 
 
Acquisition
 
 
Shares held in escrow (in shares)
180,000 
687,885 
Shares issued as part of purchase price (in shares)
389,733 
389,733 
Shares subject to performance conditions (in shares)
 
127,054 
Preferred Stock |
Series T Preferred Stock |
Former Shareholder of Acquiree
 
 
Acquisition
 
 
Shares subject to graded vesting (in shares)
507,885 
507,885 
Graded vesting period (in years)
3 years 
3 years 
Fair value
$ 4.0 
$ 4.0 
Stockholders' Equity - Convertible Preferred Stock - Conversion (Details) (Convertible preferred stock, USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2015
Convertible preferred stock
 
Conversion
 
Ratio for option to convert into common stock
Minimum IPO price for conversion
$ 50.0 
Voting power (as a percent)
50.00% 
Stockholders' Equity - Convertible Preferred Stock - Voting (Details)
Dec. 31, 2015
director
Vote
Stockholders' Equity
 
Votes per share
Common stock, number of directors
Series A Preferred Stock
 
Stockholders' Equity
 
Preferred stock, number of directors
Series B Preferred Stock
 
Stockholders' Equity
 
Preferred stock, number of directors
Series D Preferred Stock
 
Stockholders' Equity
 
Preferred stock, number of directors
Minimum number of shares required for voting (in shares)
2,000,000 
Stockholders' Equity - Convertible Preferred Stock - Dividends (Details) (Convertible preferred stock, USD $)
In Millions, unless otherwise specified
6 Months Ended 12 Months Ended
Jun. 30, 2016
Dec. 31, 2015
Convertible preferred stock
 
 
Convertible Preferred Stock
 
 
Dividends declared and paid
$ 0 
$ 0 
Stockholders' Equity - Convertible Preferred Stock - Liquidation Preference (Details)
Dec. 31, 2015
Series A Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 0.35 
Series B Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 1.05 
Series C Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 2.99 
Series D Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 7.42 
Series E Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 11.31 
Series T Preferred Stock
 
Convertible Preferred Stock
 
Original issue price per share (in dollars per share)
$ 0.01 
Stockholders' Equity - Preferred Stock (Details) (USD $)
Dec. 31, 2017
Dec. 31, 2016
Preferred Stock
 
 
Preferred stock, authorized (in shares)
100,000,000 
100,000,000 
Preferred stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Preferred stock, issued (in shares)
Preferred stock, outstanding (in shares)
Stockholders' Equity - Common Stock (Details) (USD $)
Dec. 31, 2017
Dec. 31, 2016
Common Stock
 
 
Common stock, authorized (in shares)
1,100,000,000 
1,100,000,000 
Common stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Common stock, issued (in shares)
93,969,796 
87,248,548 
Common stock, outstanding (in shares)
93,969,796 
87,248,548 
Common Class A
 
 
Common Stock
 
 
Common stock, authorized (in shares)
1,000,000,000 
1,000,000,000 
Common stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Common stock, issued (in shares)
69,906,550 
49,996,410 
Common stock, outstanding (in shares)
69,906,550 
49,996,410 
Votes per share
 
Common Class B
 
 
Common Stock
 
 
Common stock, authorized (in shares)
100,000,000 
100,000,000 
Common stock, par value (in dollars per share)
$ 0.001 
$ 0.001 
Common stock, issued (in shares)
24,063,246 
37,252,138 
Common stock, outstanding (in shares)
24,063,246 
37,252,138 
Votes per share
10 
 
Stockholders' Equity - Shares Held in Escrow (Details) (Common Class B, Authy, Inc.)
Dec. 31, 2017
Dec. 31, 2016
Common Class B |
Authy, Inc.
 
 
Shares held in escrow
 
 
Shares held in escrow (in shares)
180,000 
180,000 
Stockholders' Equity - Common Stock Shares Reserved (Details)
Dec. 31, 2017
Dec. 31, 2016
Sep. 2, 2015
Stockholders' Equity
 
 
 
Common stock reserved for Twilio.org (in shares)
 
 
888,022 
Reserved shares of common stock (in shares)
27,446,461 
28,104,671 
 
2016 Stock Option and Incentive Plan
 
 
 
Stockholders' Equity
 
 
 
Stock - based awards available for grant (in shares)
10,200,189 
10,143,743 
 
Common Class A
 
 
 
Stockholders' Equity
 
 
 
Common stock reserved for Twilio.org (in shares)
635,014 
680,397 
 
Stock Options
 
 
 
Stockholders' Equity
 
 
 
Stock options issued and outstanding (in shares)
10,710,427 
14,649,276 
 
Restricted Stock Units (RSUs)
 
 
 
Stockholders' Equity
 
 
 
Nonvested restricted stock units issued and outstanding (in shares)
5,665,459 
2,034,217 
 
Employee Stock |
Common Class A
 
 
 
Stockholders' Equity
 
 
 
Common stock reserved for issuance under an ESPP (in shares)
235,372 
597,038 
 
Stockholders' Equity - Stock Repurchases (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended 0 Months Ended 12 Months Ended 0 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2017
Research and development
Dec. 31, 2016
Research and development
Dec. 31, 2015
Research and development
Dec. 31, 2017
Sales and marketing
Dec. 31, 2016
Sales and marketing
Dec. 31, 2015
Sales and marketing
Dec. 31, 2017
General and administrative
Dec. 31, 2016
General and administrative
Dec. 31, 2015
General and administrative
Aug. 21, 2015
2015 Repurchase
Dec. 31, 2015
2015 Repurchase
Dec. 31, 2015
2015 Repurchase
Research and development
Dec. 31, 2015
2015 Repurchase
Sales and marketing
Dec. 31, 2015
2015 Repurchase
General and administrative
Aug. 21, 2015
2015 Repurchase
Common Stock
Aug. 21, 2015
2015 Repurchase
Series A And B Preferred Stock
Stock Repurchases
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Number of shares repurchased (in shares)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1,869,156 
365,916 
Repurchases of stock
$ 100 
$ 2 
$ 20,810 
 
 
 
 
 
 
 
 
 
$ 22,800 
 
 
 
 
 
 
Stock-based compensation expense
$ 49,619 
$ 24,225 
$ 8,877 
$ 22,808 
$ 12,946 
$ 4,046 
$ 9,822 
$ 4,972 
$ 2,389 
$ 16,339 
$ 6,016 
$ 2,377 
 
$ 2,000 
$ 800 
$ 100 
$ 1,100 
 
 
Stockholders' Equity - Twilio.org (Details) (USD $)
0 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended
May 13, 2016
Dec. 31, 2016
Oct. 31, 2016
Dec. 31, 2017
Sep. 2, 2015
Nov. 30, 2017
Common Class A
Oct. 31, 2016
Common Class A
Dec. 31, 2017
Common Class A
Dec. 31, 2016
Common Class A
Stockholders' Equity
 
 
 
 
 
 
 
 
 
Common stock reserved for Twilio.org (in shares)
 
 
 
 
888,022 
 
 
635,014 
680,397 
Twilio.org, percentage of outstanding capital stock (as a percent)
 
 
 
 
1.00% 
 
 
 
 
Twilio.org, authorized reduction in shares reserved (in shares)
107,625 
 
 
 
 
 
100,000 
 
 
Aggregate proceeds reserved for Twilio.org
 
 
$ 3,900,000 
 
 
 
 
 
 
Donation of proceeds into Donor Advised Fund
 
3,900,000 
 
 
 
 
 
 
 
Twilio.org, reserved shares, issued (in shares)
 
 
 
 
 
45,383 
 
 
 
Twilio.org, reserved shares, issued fair value
 
 
 
$ 1,172,000 
 
$ 1,200,000 
 
 
 
Stock-Based Compensation - 2008 Stock Option Plan (Details) (2008 Stock Option Plan)
Dec. 31, 2017
2008 Stock Option Plan
 
Stock Based Compensation
 
Shares available for future issuance (in shares)
Stock-Based Compensation - 2016 Stock Option Plan (Details)
12 Months Ended 1 Months Ended 12 Months Ended 0 Months Ended
Dec. 31, 2017
Employee and Nonemployee Stock Options
Dec. 31, 2017
Employee and Nonemployee Stock Options
First vesting
Dec. 31, 2017
Restricted Stock Units (RSUs)
Jul. 31, 2017
Restricted Stock Units (RSUs)
Granted in July 2017
Dec. 31, 2017
Restricted Stock Units (RSUs)
First vesting
Jan. 1, 2017
2016 Stock Option and Incentive Plan
Dec. 31, 2017
2016 Stock Option and Incentive Plan
Jun. 21, 2016
2016 Stock Option and Incentive Plan
Common Class A
Dec. 31, 2017
2016 Stock Option and Incentive Plan
Employee and Nonemployee Stock Options
Stock Based Compensation
 
 
 
 
 
 
 
 
 
Shares reserved for issuance (in shares)
 
 
 
 
 
 
 
11,500,000 
 
Maximum automatic annual increase as a percentage of outstanding common shares
 
 
 
 
 
 
5.00% 
 
 
Automatic increase in shares available for grant (in shares)
 
 
 
 
 
4,362,427 
 
 
 
Minimum grant price as a percentage of fair market value per share of the underlying common stock on the date of grant (as a percent)
 
 
 
 
 
 
 
 
100.00% 
Expiration term
10 years 
 
 
 
 
 
 
 
 
Vesting period
4 years 
1 year 
4 years 
4 years 
1 year 
 
 
 
 
Percentage of vesting rights
 
25.00% 
 
 
25.00% 
 
 
 
 
Stock-Based Compensation - 2016 Employee Stock Purchase Plan (Details) (Employee Stock, USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended 12 Months Ended 3 Months Ended
Jan. 1, 2017
Dec. 31, 2017
Dec. 31, 2017
Common Class A
Jun. 21, 2016
Common Class A
Jun. 30, 2018
Common Class A
Forecast
Stock Based Compensation
 
 
 
 
 
Shares reserved for issuance (in shares)
 
 
 
2,400,000 
 
Maximum automatic annual increase (in shares)
 
1,800,000 
 
 
 
Maximum automatic annual increase as a percentage of outstanding common shares
 
1.00% 
 
 
 
Automatic increase in shares available for grant (in shares)
872,485 
 
 
 
 
Discount from market price, offering date (as a percent)
 
 
15.00% 
 
 
Discount from market price, purchase date (as a percent)
 
 
15.00% 
 
 
Purchase price, percentage of fair market value (as a percent)
 
 
85.00% 
 
 
Shares purchased (in shares)
 
 
794,142 
 
235,372 
Unrecognized compensation cost, other than options
 
$ 1.1 
 
 
 
Weighted-average period (in years)
 
4 months 24 days 
 
 
 
Stock-Based Compensation - Stock Option Activity (Details) (Employee and Nonemployee Stock Options, USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Employee and Nonemployee Stock Options
 
 
Number of options outstanding
 
 
Outstanding options as of the beginning of the period (in shares)
14,649,276 
 
Granted (in shares)
1,526,450 
 
Exercised (in shares)
(5,194,905)
 
Forfeited and cancelled (in shares)
(825,394)
 
Outstanding options as of the end of the period (in shares)
10,155,427 
14,649,276 
Weighted-average exercise price (per share)
 
 
Outstanding options as of the beginning of the period (in dollars per share)
$ 6.14 
 
Granted (in dollars per share)
$ 30.66 
 
Exercised (in dollars per share)
$ 4.93 
 
Forfeited and cancelled (in dollars per share)
$ 7.76 
 
Outstanding options as of the end of the period (in dollars per share)
$ 10.31 
$ 6.14 
Weighted-average remaining contractual term and aggregate intrinsic value
 
 
Weighted-average remaining contractual term (in years)
7 years 1 month 13 days 
7 years 6 months 7 days 
Aggregate intrinsic value
$ 145,763 
$ 332,716 
Options vested and exercisable and options vested and expected to vest
 
 
Options vested and exercisable - number of options outstanding (in shares)
5,278,003 
 
Options vested and exercisable - weighted-average exercise price (in dollars per share)
$ 5.53 
 
Options vested and exercisable - weighted-average remaining contractual term (in years)
6 years 3 months 11 days 
 
Options vested and exercisable - aggregate intrinsic value
$ 95,354 
 
Stock-Based Compensation - Stock Options - Additional Information (Details) (Employee and Nonemployee Stock Options, USD $)
In Millions, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Employee and Nonemployee Stock Options
 
 
 
Stock Based Compensation
 
 
 
Aggregate intrinsic value of stock options exercised
$ 132.0 
$ 54.4 
$ 10.1 
Grant date fair value of options vested
$ 15.8 
$ 15.3 
$ 8.2 
Weighted-average grant date fair value of options granted (in dollars per share)
$ 13.33 
$ 5.52 
$ 4.30 
Stock-Based Compensation - Performance-Based Stock Options (Details) (USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended 12 Months Ended
Feb. 28, 2017
item
Dec. 31, 2017
Performance-based stock options
 
 
Stock-Based Compensation
 
 
Number of distinct awards
 
Total grant value
$ 5.9 
 
Vesting period upon satisfaction of performance condition
24 months 
 
Performance condition achievement window
4 years 3 months 18 days 
 
Expiration term
7 years 
 
Number of options outstanding
 
 
Granted (in shares)
555,000 
555,000 
Outstanding options as of the end of the period (in shares)
 
555,000 
Weighted-average exercise price (per share)
 
 
Granted (in dollars per share)
 
$ 31.72 
Outstanding options as of the end of the period (in dollars per share)
 
$ 31.72 
Weighted-average remaining contractual term
 
 
Weighted-average remaining contractual term (in years)
 
6 years 
Performance-based stock options, $13.48 grant date fair value
 
 
Stock-Based Compensation
 
 
Grant date fair value (in dollars per share)
$ 13.48 
 
Derived service period as adjusted
3 years 4 months 24 days 
 
Performance-based stock options, $10.26 grant date fair value
 
 
Stock-Based Compensation
 
 
Grant date fair value (in dollars per share)
$ 10.26 
 
Derived service period as adjusted
4 years 7 months 6 days 
 
Performance-based stock options, $8.41 grant date fair value
 
 
Stock-Based Compensation
 
 
Grant date fair value (in dollars per share)
$ 8.41 
 
Derived service period as adjusted
5 years 3 months 18 days 
 
Stock-Based Compensation - Stock Options - Unrecognized Compensation Cost (Details) (Employee and Nonemployee Stock Options, USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Employee and Nonemployee Stock Options
 
Stock Based Compensation
 
Unrecognized compensation cost, options
$ 34.8 
Weighted-average period (in years)
2 years 1 month 13 days 
Stock-Based Compensation - Restricted Stock Units Activity (Details) (Restricted Stock Units (RSUs), USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Restricted Stock Units (RSUs)
 
 
Number of units outstanding
 
 
Nonvested RSUs at the beginning of the period (in shares)
2,034,217 
 
Granted (in shares)
4,826,508 
 
Vested (in shares)
(711,371)
 
Forfeited and cancelled (in shares)
(483,895)
 
Nonvested RSUs at the end of the period (in shares)
5,665,459 
 
Weighted-average grant date fair value (per share)
 
 
Nonvested RSUs at the beginning of the period (in dollars per share)
$ 32.66 
 
Granted (in dollars per share)
$ 28.05 
 
Vested (in dollars per share)
$ 30.29 
 
Forfeited and cancelled (in dollars per share)
$ 29.53 
 
Nonvested RSUs at the end of the period (in dollars per share)
$ 29.29 
 
Aggregate intrinsic value
 
 
Aggregate intrinsic value
$ 133,648 
$ 58,687 
Stock-Based Compensation - Restricted Stock Units - Additional Information (Details)
12 Months Ended
Dec. 31, 2017
Restricted Stock Units (RSUs), Pre-IPO
 
Stock Based Compensation
 
Service condition period (in years)
4 years 
Restricted Stock Units (RSUs), Post-IPO |
Minimum
 
Stock Based Compensation
 
Service condition period (in years)
2 years 
Restricted Stock Units (RSUs), Post-IPO |
Maximum
 
Stock Based Compensation
 
Service condition period (in years)
4 years 
Stock-Based Compensation - Restricted Stock Units - Unrecognized Compensation Cost (Details) (Restricted Stock Units (RSUs), USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Restricted Stock Units (RSUs)
 
Stock Based Compensation
 
Unrecognized compensation cost, other than options
$ 148.0 
Weighted-average period (in years)
3 years 3 months 18 days 
Stock-Based Compensation - Equity Awards Granted to Nonemployees (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Sep. 30, 2016
Nonemployee Restricted Stock Units
Dec. 31, 2017
Nonemployee Restricted Stock Units
Dec. 31, 2016
Nonemployee Restricted Stock Units
Dec. 31, 2015
Nonemployee Stock Option
Dec. 31, 2016
Nonemployee Stock Option
Dec. 31, 2017
Nonemployee Stock Option
Stock Based Compensation
 
 
 
 
 
 
 
 
 
Restricted stock unit awards outstanding (in shares)
 
 
 
 
 
 
 
 
Stock option awards outstanding (in shares)
 
 
 
 
 
 
 
 
Restricted stock units granted (in shares)
 
 
 
30,255 
 
 
 
 
 
Stock options granted (in shares)
 
 
 
 
 
 
30,000 
 
 
Stock-based compensation expense
$ 49,619 
$ 24,225 
$ 8,877 
 
$ 400 
$ 600 
 
$ 300 
 
Stock-Based Compensation - Early Exercises of Nonvested Options (Details) (Employee Stock Option, 2008 Stock Option Plan, USD $)
In Millions, except Share data, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Employee Stock Option |
2008 Stock Option Plan
 
 
Stock Based Compensation
 
 
Liability for unvested shares
$ 0.03 
$ 0.30 
Unvested shares that were early exercised (in shares)
5,214 
49,580 
Stock-Based Compensation - Valuation Assumptions (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Valuation Assumptions
 
 
 
Dividend rate (as a percent)
0.00% 
 
 
Employee Stock Option
 
 
 
Valuation Assumptions
 
 
 
Expected term (in years)
6 years 29 days 
6 years 29 days 
6 years 29 days 
Expected volatility, low end of range (as a percent)
44.30% 
51.40% 
47.80% 
Expected volatility, high end of range (as a percent)
47.60% 
53.00% 
54.90% 
Risk-free interest rate, low end of range (as a percent)
1.90% 
1.30% 
1.40% 
Risk-free interest rate, high end of range (as a percent)
2.30% 
1.50% 
2.00% 
Dividend rate (as a percent)
0.00% 
0.00% 
0.00% 
Employee Stock
 
 
 
Valuation Assumptions
 
 
 
Expected term (in years)
6 months 
10 months 24 days 
 
Expected volatility (as a percent)
 
52.00% 
 
Expected volatility, low end of range (as a percent)
33.20% 
 
 
Expected volatility, high end of range (as a percent)
33.90% 
 
 
Risk-free interest rate (as a percent)
 
0.60% 
 
Risk-free interest rate, low end of range (as a percent)
1.10% 
 
 
Risk-free interest rate, high end of range (as a percent)
1.40% 
 
 
Dividend rate (as a percent)
0.00% 
0.00% 
 
Performance-based stock options
 
 
 
Valuation Assumptions
 
 
 
Asset volatility (as a percent)
40.00% 
 
 
Equity volatility (as a percent)
45.00% 
 
 
Discount rate (as a percent)
14.00% 
 
 
Stock price at grant date (in dollars per share)
$ 31.72 
 
 
Minimum |
Employee Stock Option
 
 
 
Valuation Assumptions
 
 
 
Fair value of common stock (in dollars per share)
$ 23.60 
$ 10.09 
$ 7.07 
Maximum |
Employee Stock Option
 
 
 
Valuation Assumptions
 
 
 
Fair value of common stock (in dollars per share)
$ 31.96 
$ 15.00 
$ 10.09 
Stock-Based Compensation - Stock-Based Compensation Expense (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Stock-Based Compensation Expense
 
 
 
Stock-based compensation expense
$ 49,619 
$ 24,225 
$ 8,877 
Cost of revenue
 
 
 
Stock-Based Compensation Expense
 
 
 
Stock-based compensation expense
650 
291 
65 
Research and development
 
 
 
Stock-Based Compensation Expense
 
 
 
Stock-based compensation expense
22,808 
12,946 
4,046 
Sales and marketing
 
 
 
Stock-Based Compensation Expense
 
 
 
Stock-based compensation expense
9,822 
4,972 
2,389 
General and administrative
 
 
 
Stock-Based Compensation Expense
 
 
 
Stock-based compensation expense
$ 16,339 
$ 6,016 
$ 2,377 
Net Loss Per Share Attributable to Common Stockholders - Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Net Loss Per Share Attributable to Common Stockholders
 
 
 
Net loss attributable to common stockholders
$ (63,708)
$ (41,324)
$ (38,896)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted (in shares)
91,224,607 
53,116,675 
17,746,526 
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)
$ (0.70)
$ (0.78)
$ (2.19)
Net Loss Per Share Attributable to Common Stockholders - Anti-Dilutive Securities (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Anti-dilutive securities
 
 
 
Total
17,251,486 
18,010,508 
72,403,707 
Convertible preferred stock
 
 
 
Anti-dilutive securities
 
 
 
Total
 
 
54,508,441 
Employee and Nonemployee Stock Options
 
 
 
Anti-dilutive securities
 
 
 
Total
10,710,427 
14,649,276 
16,883,837 
Restricted Stock Units (RSUs)
 
 
 
Anti-dilutive securities
 
 
 
Total
5,665,459 
2,034,217 
71,000 
Class A common stock reserved for Twilio.org
 
 
 
Anti-dilutive securities
 
 
 
Total
635,014 
680,397 
888,022 
Employee Stock
 
 
 
Anti-dilutive securities
 
 
 
Total
235,372 
597,038 
 
Unvested shares subject to repurchase
 
 
 
Anti-dilutive securities
 
 
 
Total
5,214 
49,580 
52,407 
Net Loss Per Share Attributable to Common Stockholders - Shares Held in Escrow (Details) (Authy, Inc., Preferred Stock, Series T Preferred Stock)
Dec. 31, 2015
Feb. 28, 2015
Authy, Inc. |
Preferred Stock |
Series T Preferred Stock
 
 
Shares held in escrow
 
 
Shares held in escrow (in shares)
687,885 
180,000 
Income Taxes - Domestic and Foreign Components of Loss Before Income Taxes (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Taxes
 
 
 
United States
$ (46,737)
$ (14,002)
$ (23,962)
International
(16,266)
(26,996)
(11,420)
Loss before provision for income taxes
$ (63,003)
$ (40,998)
$ (35,382)
Income Taxes - Provision for Income Taxes (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Current:
 
 
 
Federal
$ 99 
 
 
State
78 
83 
45 
Foreign
823 
214 
213 
Total
1,000 
297 
258 
Deferred:
 
 
 
Federal
28 
(109)
State
10 
 
 
Foreign
(333)
27 
(27)
Total
(295)
29 
(136)
Provision for income taxes
$ 705 
$ 326 
$ 122 
Income Taxes - Reconciliation of the Statutory Federal Tax Rate and the Effective Tax Rate (Details)
0 Months Ended 12 Months Ended
Dec. 22, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Taxes
 
 
 
 
Tax benefit at federal statutory rate
35.00% 
34.00% 
34.00% 
34.00% 
State tax, net of federal benefit
 
10.00% 
11.00% 
(3.00%)
Stock-based compensation
 
47.00% 
23.00% 
(8.00%)
Credits
 
8.00% 
2.00% 
4.00% 
Foreign rate differential
 
(8.00%)
(23.00%)
(11.00%)
Reserve for uncertain tax positions
 
 
(12.00%)
 
Change in valuation allowance
 
(46.00%)
(34.00%)
(14.00%)
Change in federal statutory rate
 
(45.00%)
 
 
Other
 
(1.00%)
(2.00%)
(2.00%)
Effective tax rate
 
(1.00%)
(1.00%)
0.00% 
Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Deferred tax assets:
 
 
 
Net operating loss carryforwards
$ 56,138 
$ 31,090 
$ 27,401 
Accrued and prepaid expenses
9,140 
16,698 
7,603 
Stock-based compensation
7,131 
5,368 
1,433 
Research and development credits
16,212 
7,807 
6,022 
Charitable contributions
1,233 
1,458 
 
Other
472 
 
 
Gross deferred tax assets
90,326 
62,421 
42,459 
Valuation allowance
(78,900)
(49,601)
(35,613)
Net deferred tax assets
11,426 
12,820 
6,846 
Deferred tax liabilities:
 
 
 
Capitalized software
(7,664)
(7,086)
(4,084)
Prepaid expenses
(1,015)
(452)
(2,035)
Acquired intangibles
(2,101)
(152)
(460)
Property and equipment
(2,380)
(4,931)
(240)
Deferred commissions
(718)
(201)
 
Net deferred tax asset
 
 
27 
Net deferred tax liability
$ (2,452)
$ (2)
 
Income Taxes - Net Operating Loss Carryforwards (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2017
Federal
 
Income Taxes
 
Net operating loss carryforwards
$ 229.3 
State
 
Income Taxes
 
Net operating loss carryforwards
$ 159.6 
Income Taxes - Tax Credits (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2017
Federal
 
Income Taxes
 
Tax credits
$ 12.6 
State
 
Income Taxes
 
Tax credits
$ 11.0 
Income Taxes - Additional Information (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Income Taxes
 
 
Increase in valuation allowance
$ 29.3 
$ 14.0 
Income Taxes - Unrecognized Tax Benefits - Reconciliation (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Taxes
 
 
 
Unrecognized tax benefit, beginning of year
$ 12,275 
$ 1,679 
$ 1,024 
Gross increases for tax positions of prior years
493 
1,996 
 
Gross decrease for tax positions of prior years
(6,331)
 
 
Gross increases for tax positions of current years
3,008 
8,600 
655 
Unrecognized tax benefit, end of year
$ 9,445 
$ 12,275 
$ 1,679 
Income Taxes - Unrecognized Tax Benefit - Additional Information (Details) (USD $)
Dec. 31, 2017
Income Taxes
 
Unrecognized tax benefit that would impact the effective tax rate if recognized
$ 400,000 
Accumulated interest and penalties related to uncertain tax positions
$ 35,000 
Income Taxes - Tax Cuts and Jobs Act (Details) (USD $)
In Millions, unless otherwise specified
0 Months Ended 12 Months Ended
Dec. 22, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2018
Forecast
Tax Cuts and Jobs Act
 
 
 
 
 
U.S. corporate income tax rate (as a percent)
35.00% 
34.00% 
34.00% 
34.00% 
21.00% 
Decrease to federal and state deferred tax assets
 
$ 28.0 
 
 
 
Decrease to deferred tax assets valuation allowance
 
28.0 
 
 
 
Adjustment to income tax expense related to remeasurement of deferred tax assets
 
 
 
 
Provisional amount for incomplete accounting
 
$ 0 
 
 
 
Percentage of pro rata share in CFC for determining GILTI requirements
 
10.00% 
 
 
 
Employee Benefit Plan (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Employee Benefit Plan
 
 
 
Employer contributions
$ 1.8 
$ 1.1 
$ 0 
Transactions with Investors - Vendor Ownership Interest (Details)
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Vendor 1 |
Twilio Inc.
 
 
 
Transactions With Investors
 
 
 
Ownership percentage (as a percent)
1.90% 
2.00% 
2.50% 
Vendor 2 |
Twilio Inc.
 
 
 
Transactions With Investors
 
 
 
Ownership percentage (as a percent)
1.00% 
1.00% 
1.20% 
Investor
 
 
 
Transactions With Investors
 
 
 
Vendors, number
Transactions with Investors - Vendor Transactions (Details) (Investor, USD $)
In Millions, unless otherwise specified
1 Months Ended 12 Months Ended
Oct. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Vendor 1
 
 
 
 
Transactions With Investors
 
 
 
 
Purchases from vendor
 
$ 20.4 
$ 14.5 
$ 11.1 
Amount due to vendor
 
0.2 
 
Amount due from vendor
 
1.2 
0.3 
 
Purchase agreement period (in years)
3 years 
 
 
 
Purchase commitment amount
57.7 
 
 
 
Vendor 2
 
 
 
 
Transactions With Investors
 
 
 
 
Purchases from vendor
 
0.8 
0.5 
0.5 
Amount due from vendor
 
$ 0 
$ 1.0