Etsy (ETSY) 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 14, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	ETSY INC
Entity Central Index Key	1,370,637
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		115,568,802

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 188,030	$ 271,244
Short-term investments	82,338	21,620
Accounts receivable, net of allowance for doubtful accounts of $2,071 and $1,997 as of December 31, 2015 and September 30, 2016, respectively	20,886	20,275
Prepaid and other current assets	10,840	9,521
Deferred tax charge—current	17,132	17,132
Funds receivable and seller accounts	34,180	19,262
Total current assets	353,406	359,054
Restricted cash	5,341	5,341
Property and equipment, net of accumulated depreciation and amortization of $38,091 and $42,690 as of December 31, 2015 and September 30, 2016, respectively	123,708	105,021
Goodwill	37,765	27,752
Intangible assets, net	8,772	2,871
Deferred tax charge—net of current portion	39,169	51,396
Other assets	1,040	1,626
Total assets	569,201	553,061
Current liabilities:
Accounts payable	7,323	14,382
Accrued expenses	20,037	31,253
Capital lease obligations—current	6,563	5,610
Funds payable and amounts due to sellers	34,180	19,262
Deferred revenue	5,595	4,712
Other current liabilities	3,880	4,903
Total current liabilities	77,578	80,122
Capital lease obligations—net of current portion	5,325	7,571
Deferred tax liabilities	62,882	61,420
Facility financing obligation	55,214	51,804
Other liabilities	23,746	21,646
Total liabilities	224,745	222,563
Stockholders’ equity:
Common stock ($0.001 par value, 1,400,000,000 shares authorized as of December 31, 2015 and September 30, 2016; 112,563,354 and 115,340,742 shares issued and outstanding as of December 31, 2015 and September 30, 2016, respectively)	115	113
Additional paid-in capital	433,894	406,020
Accumulated deficit	(94,958)	(86,440)
Accumulated other comprehensive income	5,405	10,805
Total stockholders’ equity	344,456	330,498
Total liabilities and stockholders’ equity	$ 569,201	$ 553,061

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,997	$ 2,071
Accumulated depreciation and amortization	$ 42,690	$ 38,091
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	1,400,000,000	1,400,000,000
Common stock, shares issued (in shares)	115,340,742	112,563,354
Common stock, shares outstanding (in shares)	115,340,742	112,563,354

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenue	$ 87,562	$ 65,696	$ 254,758	$ 185,604
Cost of revenue	29,314	24,165	86,323	66,783
Gross profit	58,248	41,531	168,435	118,821
Operating expenses:
Marketing	18,736	16,542	51,788	44,295
Product development	14,897	11,406	38,967	31,487
General and administrative	21,942	15,250	63,555	53,339
Total operating expenses	55,575	43,198	154,310	129,121
(Loss) income from operations	2,673	(1,667)	14,125	(10,300)
Other expense:
Interest expense and amortization of deferred financing costs	(2,448)	(512)	(4,789)	(1,056)
Interest and other income	402	59	1,313	117
Net unrealized gain (loss) on warrant and other liabilities	0	3	0	(3,136)
Foreign exchange (loss) gain	1,337	(679)	3,071	(15,727)
Total other expense	(709)	(1,129)	(405)	(19,802)
(Loss) income before income taxes	1,964	(2,796)	13,720	(30,102)
Provision for income taxes	(4,363)	(4,095)	(22,238)	(19,729)
Net loss	$ (2,399)	$ (6,891)	$ (8,518)	$ (49,831)
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.02)	$ (0.06)	$ (0.08)	$ (0.59)
Weighted average common shares outstanding:
Basic and diluted (in shares)	113,757,212	111,329,917	112,980,639	84,195,227

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (2,399)	$ (6,891)	$ (8,518)	$ (49,831)
Other comprehensive (loss) income:
Cumulative translation adjustment	(2,014)	(235)	(5,442)	10,177
Unrealized gains (losses) on marketable securities, net of tax	(66)	3	42	8
Total other comprehensive (loss) income	(2,080)	(232)	(5,400)	10,185
Comprehensive loss	$ (4,479)	$ (7,123)	$ (13,918)	$ (39,646)

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders’ Equity (Unaudited) - 9 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Balance as of December 31, 2015 at Dec. 31, 2015	$ 330,498	$ 113	$ 406,020	$ (86,440)	$ 10,805
Balance as of December 31, 2015 (in shares) at Dec. 31, 2015		112,563,354
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	9,504		9,504
Exercise of vested options	$ 7,808	$ 2	7,806
Exercise of vested options (in shares)	1,961,245	1,961,245
Vesting of restricted stock units, net of shares withheld	$ (633)		(633)
Vesting of restricted stock units, net of shares withheld (in shares)		86,729
Exercise of warrants	159		159
Exercise of warrants (in shares)		97,931
Shares withheld in net exercise of warrants	(159)		(159)
Shares withheld in net exercise of warrants (in shares)		(17,920)
Retirement of restricted shares	0		0
Retirement of restricted shares (in shares)		(36,346)
Issuance of common stock	6,965		6,965
Issuance of common stock (in shares)		685,749
Stock-based compensation—acquisitions	681		681
Conversion of liability-classified restricted shares upon vesting	1,942		1,942
Excess tax benefit from the exercise of options	1,609		1,609
Other comprehensive loss	(5,400)				(5,400)
Net loss	(8,518)			(8,518)
Balance as of September 30, 2016 at Sep. 30, 2016	$ 344,456	$ 115	$ 433,894	$ (94,958)	$ 5,405
Balance as of September 30, 2016 (in shares) at Sep. 30, 2016		115,340,742

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities
Net loss	$ (8,518)	$ (49,831)
Adjustments to reconcile net loss to net cash provided by operating activities:
Stock-based compensation expense	9,008	6,559
Stock-based compensation expense—acquisitions	2,582	3,158
Contribution of stock to Good Work Institute (formerly Etsy.org)	0	3,200
Depreciation and amortization expense	15,620	14,041
Bad debt expense	1,215	1,473
Foreign exchange loss (gain)	(3,071)	15,727
Amortization of debt issuance costs	137	122
Non-cash interest expense	3,274	0
Interest on marketable securities	840	0
Net unrealized loss on warrant and other liabilities	0	3,136
Loss on disposal of assets	1,134	476
Amortization of deferred tax charge	12,227	15,093
Excess tax benefit from exercise of stock options	(1,609)	(2,472)
Changes in operating assets and liabilities:
Accounts receivable	(1,750)	(1,967)
Funds receivable and seller accounts	(14,759)	(6,710)
Prepaid expenses and other current assets	410	535
Other assets	436	152
Accounts payable	(6,059)	(3,530)
Accrued liabilities	(466)	17,719
Funds payable and amounts due to sellers	14,759	6,710
Deferred revenue	831	671
Other liabilities	2,000	(5,255)
Net cash provided by operating activities	28,241	19,007
Cash flows from investing activities
Acquisition of business, net of cash acquired	(7,880)	0
Purchases of property and equipment	(34,153)	(9,524)
Development of internal-use software	(8,441)	(7,329)
Purchases of marketable securities	(108,652)	(18,552)
Sales of marketable securities	47,136	17,270
Net cash used in investing activities	(111,990)	(18,135)
Cash flows from financing activities
Repurchase of stock	(633)	0
Proceeds from public offering	0	199,467
Proceeds from exercise of stock options	7,808	2,285
Excess tax benefit from the exercise of stock options	1,609	2,472
Payments on capitalized lease obligations	(4,382)	(2,262)
Deferred payments on acquisition of business	(649)	0
Payments relating to public offering	0	(2,919)
Net cash provided by financing activities	3,753	199,043
Effect of exchange rate changes on cash	(3,218)	(3,291)
Net increase (decrease) in cash and cash equivalents	(83,214)	196,624
Cash and cash equivalents at beginning of period	271,244	69,659
Cash and cash equivalents at end of period	188,030	266,283
Supplemental non-cash disclosures
Equipment acquired under capital lease obligations	3,088	8,273
Stock-based compensation capitalized in development of capitalized software	496	342
Non-cash additions to development of internal-use software and property and equipment	1,362	797
Non-cash addition to construction in progress related to build-to-suit lease and facility financing obligation	0	6,608
Non-cash addition to capitalized public offering costs	0	969
Fair value of common stock issued in acquisition	$ 6,966	$ 0

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Note 1—Basis of Presentation and Summary of Significant Accounting Policies Description of Business Etsy, Inc. (the “Company” or “Etsy”) was incorporated in Delaware in February 2006. Etsy operates a marketplace where people around the world connect, both online and offline, to make, sell and buy unique goods. The Company generates revenue primarily from transaction and listing fees, Direct Checkout fees, Promoted Listings fees and Shipping Label sales. Initial Public Offering On April 21, 2015, the Company completed an initial public offering (the “IPO”) in which it issued and sold 13,333,333 shares of common stock at a public offering price of $16.00 per share. The Company received net proceeds of $194.4 million after deducting underwriting discounts of $13.9 million and other offering expenses of approximately $5.1 million . These expenses were recorded against the proceeds received from the IPO. Certain selling stockholders sold an additional 5,833,332 shares of common stock in the IPO. The Company did not receive any proceeds from the sale of shares by the selling stockholders. Upon the closing of the IPO, all outstanding shares of preferred stock of the Company converted into 53,448,243 shares of common stock. In addition, all outstanding warrants for preferred stock converted into warrants for 203,030 shares of common stock. The Company effected a 1-for-2 reverse split of its common stock on March 25, 2015. The reverse split combined each two shares of the Company’s issued and outstanding common stock into one share of common stock and correspondingly adjusted the conversion prices of its convertible preferred stock. No fractional shares were issued in connection with the reverse split, and any fractional shares resulting from the reverse split were rounded down to the nearest whole share. All share, per share and related information presented in the consolidated financial statements and accompanying notes have been retroactively adjusted, where applicable, to reflect the reverse stock split. Basis of Consolidation The consolidated financial statements include the accounts of Etsy and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Unaudited Interim Financial Information The accompanying consolidated balance sheet as of September 30, 2016 , the consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2015 and 2016 , the consolidated statements of cash flows for the nine months ended September 30, 2015 and 2016 and the consolidated statement of changes in stockholders’ equity for the nine months ended September 30, 2016 are unaudited. The unaudited interim financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s financial position as of September 30, 2016 , results of operations for the three and nine months ended September 30, 2015 and 2016 and cash flows for the nine months ended September 30, 2015 and 2016 . The financial data and the other information disclosed in these notes to the consolidated financial statements related to these three and nine month periods are unaudited. These unaudited interim financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 1, 2016 (the “Annual Report”). There have been no material changes in the Company's significant accounting policies from those that were disclosed in the Annual Report. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and judgments 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. The accounting estimates that require management’s most difficult and subjective judgments include revenue recognition, income taxes, website development costs and internal-use software, purchase price allocations for business combinations, valuation of goodwill and intangible assets, leases and stock-based compensation. The Company evaluates its estimates and judgments on an ongoing basis and revises them when necessary. Actual results may differ from the original or revised estimates. Income Taxes The Company's income tax provision for interim periods is determined using an estimate of its annual effective tax rate adjusted for discrete items, if any, for relevant interim periods. The Company updates its estimate of the annual effective tax rate each quarter and makes cumulative adjustments if its estimated annual tax rate changes. The Company's quarterly tax provision and quarterly estimate of its annual effective tax rate are subject to significant variations due to several factors, including variability in predicting its pretax and taxable income and the mix of jurisdictions to which those relate, changes of expenses or losses for which tax benefits are not recognized and changes in the laws, regulations and administrative practices of the jurisdictions in which the Company operates. Build-to-Suit Lease In May 2016, the Company took possession of its corporate headquarters in Brooklyn upon substantial completion of the construction phase of the build-out. Upon completion of the project, the Company performed a sale-leaseback analysis pursuant to Accounting Standards Codification (“ASC”) 840 - Leases , to determine the appropriateness of removing the previously capitalized assets from the consolidated balance sheets. The Company concluded that components of “continuing involvement” were evident as a result of this review, precluding the derecognition of the related assets from the consolidated balance sheets. In conjunction with the lease, the Company also recorded a facility financing obligation equal to the fair market value of the assets received from the landlord. At the end of the lease term, including exercise of any renewal options, the net remaining facility financing obligation over the net carrying value of the fixed asset will be recognized as a non-cash gain on sale of the property. The Company does not report rent expense for the lease. Rather, rental payments under the lease are recognized as a reduction of the financing obligation and interest expense, and the associated asset capitalized throughout the construction project is depreciated over its determined useful life. Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or FASB, issued an accounting standards update that replaces existing revenue recognition guidance. The new guidance is effective for the annual and interim periods beginning after December 15, 2017. Among other things, the updated guidance requires companies to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2014, the FASB issued an accounting standard update under which management will be required to assess an entity’s ability to continue as a going concern and provide related disclosures in certain circumstances. The new guidance is effective for annual and interim periods ending after December 15, 2016. The adoption of this guidance is not expected to have an impact on the Company’s consolidated financial statements or disclosures. In February 2016, the FASB issued an accounting standard update that requires a reporting entity to recognize right-of-use assets and lease liabilities on the balance sheet for operating leases to increase transparency and comparability. The new guidance is effective for annual and interim periods beginning after December 15, 2018, and early adoption is permitted. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In March 2016, the FASB issued an accounting standard update for share-based payment transactions that require a reporting entity to recognize excess tax benefits and deficiencies as income tax expense or benefit in the income statement. The new guidance is effective for annual and interim periods beginning after December 15, 2016, and early adoption is permitted for financial statements as of the beginning of an interim or annual reporting period. The Company will adopt this standard in the first quarter of 2017 and is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2016, the FASB issued an accounting standard update to clarify how certain cash receipts and payments are presented and classified in the statement of cash flows. The new guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted for financial statements as of the beginning of an interim or annual reporting period. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In October 2016, the FASB issued an accounting standard update to align the recognition of income tax consequences for intra-entity transfers of assets other than inventory with International Financial Reporting Standards.The new guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted for financial statements as of the beginning of an annual reporting period. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. Recently Adopted Accounting Pronouncements In April 2015, the FASB issued an accounting standard under which customers will apply the same criteria as vendors to determine whether a cloud computing arrangement contains a software license or is solely a service contract. The new standard is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no material impact to the current period consolidated financial statements. In August 2015, the FASB issued an accounting standard update to address the presentation and subsequent measurement of debt issuance costs related to line-of-credit arrangements. The guidance affirms the Company's treatment of such costs, which is to defer and present the debt issuance costs as an asset and subsequently amortize the costs over the term of the line-of-credit arrangement. The new standard is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no impact to the current period consolidated financial statements. In September 2015, the FASB issued an accounting standard update that eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The new guidance is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no impact to the current period consolidated financial statements.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Business Combination	Note 2—Business Combinations On September 19, 2016, the Company acquired all of the outstanding common stock of Blackbird Technologies, Inc. (“Blackbird”), a machine learning company, for $32.5 million . The Company completed this acquisition to improve the quality and relevance of search on Etsy.com. Total consideration for the acquisition was approximately $15.0 million , consisting of $8.1 million in cash and 513,304 shares of the Company’s common stock with a fair value of $6.9 million on the acquisition date. Additionally, the Company issued 184,230 shares of common stock or restricted stock units (“RSUs”) on the acquisition date with a fair value of $2.5 million which are tied to continuous service with the Company as an employee and are being accounted for as post-acquisition stock-based compensation expense over a three -year vesting period. The Company will pay up to an additional $8.8 million in cash and issue up to an additional 460,575 shares of RSUs post-close with a fair value of $6.2 million , both of which are also tied to continuous service with the Company as an employee and are being accounted for as post-acquisition stock-based and other compensation expense over a three -year vesting period. A portion of the consideration and post-acquisition compensation is subject to indemnification provisions. The below table summarizes the components of the Blackbird purchase price and allocation of the purchase price at fair value (in thousands): Cash paid $ 8,050 Common shares 6,966 Total purchase consideration $ 15,016 Working capital $ 81 Developed technology 7,500 Goodwill 9,407 Deferred tax liability (1,972 ) Net assets acquired $ 15,016 Goodwill recorded in connection with the Blackbird acquisition is primarily attributed to synergies arising from the acquisition and the value of the acquired workforce. None of the resulting goodwill is deductible for tax purposes. Acquired technology intangible assets will amortize over three years. The Company recorded $0.1 million of amortization expense related to the intangible asset acquired for the three and nine months ended September 30, 2016 . This purchase price allocation is preliminary and is subject to change based on finalization of the valuation of the business. The Company incurred approximately $0.5 million in acquisition-related costs, included in general and administrative expenses. This acquisition contributed $0.3 million to the Company’s consolidated net loss in the three and nine months ended September 30, 2016 . The impact to net loss was primarily due to stock-based and other compensation expenses associated with the acquisition, as well as amortization of intangibles. The following unaudited pro forma financial information presents the combined operating results of the Company and Blackbird as if the acquisition had occurred as of January 1, 2015. The unaudited pro forma financial information includes the accounting effects of the business combination, including adjustments to amortization of intangible assets, stock-based and other compensation expenses and professional fees associated with the acquisition. The unaudited pro forma information does not necessarily reflect the actual results that would have been achieved, nor is it necessarily indicative of our future consolidated results. The unaudited pro forma financial information is presented in the table below for the three and nine months ended September 30, 2015 and 2016 (in thousands except per share amounts): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Revenue $ 65,725 $ 87,835 $ 185,691 $ 255,577 Net loss (10,472 ) (3,753 ) (57,336 ) (14,235 ) Basic and diluted net loss per share (0.09 ) (0.03 ) (0.68 ) (0.13 )

Debt

Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Debt	Note 3—Debt Credit Agreement In May 2014 , the Company entered into a $35.0 million senior secured revolving credit facility pursuant to a Revolving Credit and Guaranty Agreement with several lenders (the “Credit Agreement”). In March 2015 , the Company amended the Credit Agreement to increase the credit facility to $50.0 million . In December 2015, the Company amended the Credit Agreement to clarify certain provisions relating to permitted investments and to make other immaterial updates. As amended, the Credit Agreement will mature in May 2019 . The Credit Agreement includes a letter of credit sublimit of $10.0 million and a swingline loan sublimit of $15.0 million. Borrowings under the Credit Agreement (other than swingline loans) bear interest, at the Company’s option, at (i) a base rate equal to the highest of (a) the prime rate, (b) the federal funds rate plus 0.50% and (c) an adjusted LIBOR rate for a one-month interest period plus 1.00% , in each case plus a margin ranging from 0.00% to 0.25% or (ii) an adjusted LIBOR rate plus a margin ranging from 1.00% to 1.25% . Swingline loans under the Credit Agreement bear interest at the same base rate (plus the margin applicable to borrowings bearing interest at the base rate). These margins are determined based on the total leverage ratio for the preceding four-fiscal-quarter period. The Company is also obligated to pay other customary fees for a credit facility of this size and type, including an unused commitment fee and fees associated with letters of credit. As amended, the Credit Agreement also permits the Company, in certain circumstances, to request an increase in the facility by an amount of up to $50.0 million (and in minimum amounts of $10.0 million ) at the same maturity, pricing and other terms. The amended Credit Agreement contains customary representations and warranties applicable to the Company and its subsidiaries and customary affirmative and negative covenants applicable to the Company and its restricted subsidiaries. The negative covenants include restrictions on, among other things, indebtedness, liens, investments, mergers, dispositions, transactions with affiliates and dividends and other distributions. These restrictions do not prohibit a subsidiary of the Company from making pro rata payments to the Company or any other person that owns an equity interest in such subsidiary. The amended Credit Agreement contains a financial covenant that requires the Company and its subsidiaries to maintain a total leverage ratio (defined as net debt to adjusted EBITDA) not to exceed 3.50 to 1.00 . As amended, the Credit Agreement includes customary events of default, including a change in control and a cross-default on the Company’s material indebtedness. The Company’s obligations under the Credit Agreement are secured by substantially all of the Company and its subsidiaries’ assets, and its obligations under the Credit Agreement are guaranteed by certain of the Company’s subsidiaries. At September 30, 2016 , the Company did not have any borrowings under the Credit Agreement.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	Note 4—Stock-based Compensation The Company's 2015 Equity Incentive Plan (the “2015 Plan”) provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units (“RSUs”) and performance cash awards to employees, directors and consultants. The number of shares available for issuance under the 2015 Plan may be increased annually by an amount equal to the lesser of 7,050,000 shares of common stock, 5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year, or such other amount as determined by the Company's Board of Directors. The Board of Directors approved an increase of 2,814,083 shares available for issuance under the 2015 Plan as of January 4, 2016. Any awards issued under the 2015 Plan that are forfeited by the participant will become available for future grant under the 2015 Plan. The number of shares of the Company’s common stock initially reserved for issuance under the 2015 Plan equaled the sum of 14,100,000 shares plus up to 12,653,075 shares reserved for issuance or subject to outstanding awards under the 2006 Stock Plan. At September 30, 2016 , 17,549,262 shares were authorized under the 2015 Plan, and 14,028,358 shares were available for future grant. In the three and nine months ended September 30, 2016 , the Company granted nonqualified stock options and RSUs to eligible participants. Options have a term of 10 years . For both options and RSUs, vesting is typically over a four -year period and is contingent upon continued employment with the Company on each vesting date. In general, for newly-hired employees, options vest 25% after the first year of service and ratably each month over the remaining 36 -month period. In general, for current employees who receive an additional grant, options vest ratably each month over a 48 -month period. In general, for newly-hired employees, RSUs vest 25% after the first year following the vesting commencement date, which is the first day of the fiscal quarter closest to the date of grant, and then vest ratably each quarter over the remaining 12 -quarter period. In general, for current employees who receive an additional grant, RSUs vest ratably each quarter over a 16 -quarter period following the vesting commencement date, which is the first day of the fiscal quarter closest to the date of grant . The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model using the inputs below. Prior to the IPO, the Company utilized equity valuations based on comparable publicly-traded companies, discounted free cash flows, an analysis of the Company's enterprise value and any other factors deemed relevant in estimating the fair value of its common stock. Subsequent to the IPO, the Company has used the closing price of its common stock on Nasdaq as the fair value of its common stock. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant for time periods that approximate the expected life of the option awards. Expected volatilities are based on implied volatilities from market comparisons of certain publicly traded companies and other factors. The expected term of stock options granted has been determined using the simplified method, which uses the midpoint between the vesting date and the contractual term. The requisite service period is generally four years from the date of grant. The fair value of RSUs is determined based on the closing price of the Company's common stock on Nasdaq on the grant date. The fair value of options granted in each year using the Black-Scholes pricing model has been based on the following assumptions: Three Months Ended Nine Months Ended 2015 2016 2015 2016 Volatility 44.1% - 44.7% 39.6% 40.4% - 45.0% 39.6% - 44.6% Risk-free interest rate 1.7% - 1.9% 1.1% - 1.5% 1.3% - 1.9% 1.1% - 1.9% Expected term (in years) 6.0 - 6.1 6.3 5.5 - 6.1 5.5 - 6.3 Dividend rate —% —% —% —% The following table summarizes the activity for the Company's options: Shares Weighted-Average Exercise Price Weighted-Average Remaining Contract Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2015 11,068,859 $ 6.94 Granted 1,478,569 8.95 Exercised (1,961,245 ) 3.98 Forfeited/Canceled (873,143 ) 9.50 Outstanding at September 30, 2016 9,713,040 7.61 6.60 $ 68,001,717 Total exercisable at September 30, 2016 6,563,414 5.95 5.66 56,041,779 Total vested and expected to vest at September 30, 2016 9,523,368 7.54 6.56 67,355,632 The following table summarizes the weighted average grant date fair value of options granted, intrinsic value of options exercised and fair value of awards vested in the the three and nine months ended September 30, 2015 and 2016 : Three Months Ended Nine Months Ended 2015 2016 2015 2016 Weighted average grant date fair value of options granted $ 6.70 $ 4.84 $ 7.07 $ 3.89 Intrinsic value of options exercised 1,363,740 8,129,031 12,043,023 14,239,206 Fair value of awards vested 2,231,820 1,702,647 5,824,711 7,911,377 The total unrecognized compensation at September 30, 2016 was $15.1 million , which will be recognized over a weighted-average period of 2.54 years. The following table summarizes the activity for the Company's unvested RSUs: Shares Weighted-Average Unvested at December 31, 2015 395,846 $ 13.70 Granted 2,769,633 9.82 Vested (152,888 ) 10.90 Forfeited/Canceled (160,348 ) 9.76 Unvested at September 30, 2016 2,852,243 10.31 Total expected to vest at September 30, 2016 2,630,522 10.39 The total unrecognized compensation at September 30, 2016 was $27.7 million , which will be recognized over a weighted-average period of 3.43 years. Total stock-based compensation expense included in the consolidated statements of operations is as follows (in thousands): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Cost of revenue $ 149 $ 288 $ 681 $ 738 Marketing 120 229 349 628 Product development 756 1,234 1,981 3,117 General and administrative 1,898 2,334 6,706 7,107 Total stock-based compensation expense $ 2,923 $ 4,085 $ 9,717 $ 11,590 Total stock-based compensation expense in the three months ended September 30, 2015 and 2016 includes $0.7 million and $1.1 million in acquisition-related stock-based compensation expense, respectively. Total stock-based compensation expense in the nine months ended September 30, 2015 and 2016 includes $3.2 million and $2.6 million in acquisition-related stock-based compensation expense, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Note 5—Income Taxes In January 2015, the Company implemented an updated global corporate structure to more closely align with its global operations and future expansion plans outside of the United States. The new structure changed how the Company uses its intellectual property and implemented certain intercompany arrangements. The Company believes this may eventually result in a reduction in its overall effective tax rate and other operational efficiencies. The revised structure resulted in the setup of a deferred tax liability in the amount of $66.0 million on the taxable gain created in the transaction. In addition, the Company recorded an asset of $66.0 million for the deferred tax charge representing the future income tax on the gain, which will be amortized into income tax expense through 2019. The amount of unrecognized tax benefits included in the consolidated balance sheets increased $1.3 million in the nine months ended September 30, 2016 , from $22.2 million at December 31, 2015 to $23.5 million at September 30, 2016 . In January 2015, the Company recorded an asset of $19.7 million for the deferred tax charge representing the future unrecognized tax benefit, which will be amortized into income tax expense through 2019. The total amount of unrecognized tax benefits that, if recognized, would favorably affect the effective tax rate is $10.6 million at September 30, 2016 . During the three and nine months ended September 30, 2016 , a total of $3.0 million and $12.2 million , respectively, of the deferred tax charge was amortized into tax expense ( $2.3 million and $9.4 million , respectively, related to the updated global corporate structure, and $0.7 million and $2.8 million , respectively, related to the unrecognized tax benefit thereon). At September 30, 2016 , the Company had a total deferred tax charge of $56.3 million , of which $17.1 million is expected to amortize in the next twelve months and therefore is classified as deferred tax charge—current and $39.2 million is deferred tax charge—net of current portion.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 6—Fair Value Measurements The Company has characterized its investments in marketable securities, based on the priority of the inputs used to value the investments, into a three-level fair value hierarchy. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1), and lowest priority to unobservable inputs (Level 3). If the inputs used to measure the investments fall within different levels of the hierarchy, the categorization is based on the lowest level input that is significant to the fair value measurement of the investment. Investments recorded in the accompanying consolidated balance sheet are categorized based on the inputs to valuation techniques as follows: Level 1—These are investments where values are based on unadjusted quoted prices for identical assets in an active market that the Company has the ability to access. Level 2—These are investments where values are based on quoted market prices in markets that are not active or model derived valuations in which all significant inputs are observable in active markets. Level 3—These are liabilities where values are derived from techniques in which one or more significant inputs are unobservable. The following are the major categories of assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 and September 30, 2016 (in thousands): As of December 31, 2015 Level 1 Level 2 Level 3 Total Asset Cash equivalents: Money market funds $ 212,390 $ — $ — $ 212,390 U.S. Government bills 3 — — 3 212,393 — — 212,393 Short-term investments: U.S. Government and agency bills 21,620 — — 21,620 $ 234,013 $ — $ — $ 234,013 Liability Acquisition–related contingent consideration classified as liability $ — $ — $ 2,357 $ 2,357 $ — $ — $ 2,357 $ 2,357 As of September 30, 2016 Level 1 Level 2 Level 3 Total Asset Cash equivalents: Money market funds $ 105,160 $ — $ — $ 105,160 U.S. Government bills 7,300 — — 7,300 112,460 — — 112,460 Short-term investments: Commercial paper — 5,999 — 5,999 Corporate bonds — 50,621 — 50,621 U.S. Government and agency bills 25,718 — — 25,718 25,718 56,620 — 82,338 $ 138,178 $ 56,620 $ — $ 194,798 Liability Acquisition–related contingent consideration classified as liability $ — $ — $ 2,315 $ 2,315 $ — $ — $ 2,315 $ 2,315 Level 1 instruments include money market funds and AAA-rated U.S. Government and agency securities, which are valued based on inputs including quotes from broker-dealers or recently executed transactions in the same or similar securities. Level 2 instruments include fixed-income funds consisting of investments in commercial paper and corporate bonds, which are valued based on quoted market prices in markets that are not active or model derived valuations in which all significant inputs are observable in active markets. Level 3 instruments include contingent consideration classified as a liability in connection with the acquisition of ALM. The contingent consideration is classified as a liability due to its affiliation with a related put option, which will expire upon vesting of the underlying consideration, and its fair value is determined based on the fair value of the Company's common stock at the period-end reporting date. The table below provides a reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs (Level 3) (in thousands): Nine Months Ended Balance at beginning of period $ 2,357 Acquired — Changes to liability-classified stock awards 1,900 Settled — Conversion of liability-classified restricted shares upon vesting (1,942 ) Balance at end of period $ 2,315

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Note 7—Marketable Securities Short-term investments consist of marketable securities that are available-for-sale. The cost and fair value of available-for-sale securities were as follows as of the dates indicated (in thousands): Cost Gross Gross Fair Value December 31, 2015 U.S. Government and agency bills $ 21,636 $ (16 ) $ — $ 21,620 $ 21,636 $ (16 ) $ — $ 21,620 September 30, 2016 Commercial paper $ 5,999 $ — $ — $ 5,999 Corporate bonds 50,610 (3 ) 14 50,621 U.S. Government and agency bills 25,703 — 15 25,718 $ 82,312 $ (3 ) $ 29 $ 82,338 The Company’s investments in marketable securities consist primarily of investments in fixed-income funds and AAA-rated U.S. Government and agency bills. When evaluating investments for other-than-temporary impairment, the Company reviews factors such as length of time and extent to which fair value has been below cost basis, the financial condition of the issuer and the Company’s ability and intent to hold the investment for a period of time, which may be sufficient for anticipated recovery in market value. The Company evaluates fair values for each individual security in the investment portfolio.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 8—Goodwill and Intangible Assets The following table summarizes the changes in the carrying amount of goodwill for the period indicated (in thousands): Nine Months Ended Balance as of the beginning of the period $ 27,752 Acquisitions (1) 9,407 Foreign currency translation 606 Balance as of the end of the period $ 37,765 (1) The Company notes the purchase price allocation for the acquisition of Blackbird is preliminary and the resulting goodwill is subject to change based on finalization of the valuation of the business. The Company did not recognize any goodwill impairments during the nine months ended September 30, 2016 . At December 31, 2015 and September 30, 2016 , the gross book value and accumulated amortization of intangible assets were as follows (in thousands): As of December 31, 2015 As of September 30, 2016 Gross book Accumulated Net book Gross book Accumulated Net book Trademarks $ 822 $ (427 ) $ 395 $ 839 $ (643 ) $ 196 Technology (1) 3,882 (2,340 ) 1,542 11,419 (3,303 ) 8,116 Customer relationships 1,959 (1,024 ) 935 1,997 (1,537 ) 460 Intangible assets, net $ 6,663 $ (3,791 ) $ 2,872 $ 14,255 $ (5,483 ) $ 8,772 (1) The Company notes the purchase price allocation for the acquisition of Blackbird is preliminary and gross intangible and related accumulated amortization balances are subject to change based on finalization of the valuation of the business. Amortization expense for the nine months ended September 30, 2015 and 2016 was $1.7 million and $1.6 million , respectively. Based on amounts recorded at September 30, 2016 , the Company will recognize intangible asset amortization expense for the three months ending December 31, 2016 and years ending December 31, 2017, 2018, 2019 and thereafter as follows (in thousands): 2016 $ 1,136 2017 3,365 2018 2,500 2019 1,771 Thereafter — Total amortization expense $ 8,772

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Loss Per Share	Note 9— Net Loss Per Share The following table presents the calculation of basic and diluted net loss per share for periods presented (in thousands, except share and per share data): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Net loss $ (6,891 ) $ (2,399 ) $ (49,831 ) $ (8,518 ) Basic and diluted shares: Weighted average common shares outstanding 111,329,917 113,757,212 84,195,227 112,980,639 Net loss per share attributable to common stockholders: Basic and diluted net loss per share applicable to common stockholders $ (0.06 ) $ (0.02 ) $ (0.59 ) $ (0.08 ) The following potential common shares were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented: Three Months Ended Nine Months Ended 2015 2016 2015 2016 Stock options 11,904,577 10,364,872 11,914,369 10,890,258 Restricted stock units 148,188 2,358,365 60,204 1,718,766 Warrants 203,030 — 203,030 44,677 Convertible preferred stock — — 21,731,703 — Total anti-dilutive securities 12,255,795 12,723,237 33,909,306 12,653,701

Segment and Geographic Informat

Segment and Geographic Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment and Geographic Information	Note 10—Segment and Geographic Information The Company has determined it operates as one operating and reportable segment for purposes of allocating resources and evaluating financial performance. Revenue by country is based on the billing address of the seller. The following table summarizes revenue by geographic area (in thousands): Three Months Ended Nine Months Ended 2015 2016 2015 2016 United States $ 51,593 $ 66,204 $ 145,326 $ 194,018 International 14,103 21,358 40,278 60,740 Revenue $ 65,696 $ 87,562 $ 185,604 $ 254,758 No individual international country’s revenue exceeded 10% of total revenue.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Note 11—Contingencies Non-Income Tax Contingencies The Company had reserves of $2.6 million and $1.2 million at December 31, 2015 and September 30, 2016 , respectively, for certain non-income tax obligations, representing management’s best estimate of its potential liability. The Company could also be subject to examination in various jurisdictions related to non-income tax matters. The resolution of these types of matters, if in excess of the recorded reserve, could have an adverse impact on the Company’s business. Legal Proceedings On May 13, 2015, a purported securities class action complaint ( Altayyar v. Etsy, Inc., et al. , Docket No. 1:15-cv-02785) was filed in the United States District Court for the Eastern District of New York against the Company and certain officers. The complaint was brought on behalf of a purported class consisting of all persons or entities who purchased or otherwise acquired shares of the Company's common stock from April 16, 2015 through and including May 10, 2015. It asserted violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 based on allegedly false or misleading statements and omissions with respect to, among other things, merchandise for sale on the Company's website that may be counterfeit or constitute trademark or copyright infringement. On October 22, 2015, the court appointed a lead plaintiff and lead plaintiff’s counsel. On January 21, 2016, the lead plaintiff filed an amended class action complaint alleging false or misleading statements or omissions with respect to substantially the same topics as the original complaint. The amended complaint adds certain outside directors and underwriters as defendants, expands the purported class period to be April 16, 2015 to August 4, 2015, inclusive, and asserts violations of Sections 11, 12(a)(2), and 15 of the Securities Act of 1933, as well as Sections 10(b) and 20(a) of the Securities Exchange Act of 1934. The amended complaint seeks certification as a class action and unspecified compensatory damages plus interest and attorneys' fees. The Company and the named officers and directors intend to defend themselves vigorously against this action. In light of, among other things, the early stage of the litigation, the Company is unable to predict the outcome of this matter and is unable to make a meaningful estimate of the amount or range of loss, if any, that could result from an unfavorable outcome. On July 21, 2015, a purported securities class action complaint ( Cervantes v. Dickerson, et.al ., Case No. CIV 534768) was filed in the Superior Court of State of California, County of San Mateo, against the Company, certain officers, directors and underwriters. The complaint asserts violations of Sections 11 and 15 of the Securities Act of 1933. As in the Altayyar litigation, the complaint alleges misrepresentations in the Company’s Registration Statement on Form S-1 and Prospectus with respect to, among other things, merchandise for sale on the Company's website that may be counterfeit or constitute trademark or copyright infringement. The complaint seeks certification as a class action and unspecified compensatory damages plus interest and attorneys' fees. On November 5, 2015, another purported securities class action complaint ( Weiss v. Etsy et al. , No. CIV 536123) was filed in the Superior Court of State of California, County of San Mateo. The Weiss complaint names as defendants the Company and the same officers, directors and underwriters named in the Cervantes complaint, and also asserts violations of Sections 11 and 15 of the Securities Act of 1933 based on allegedly false or misleading statements or omissions with respect to, among other things, merchandise for sale on the Company's website that may be counterfeit or constitute trademark or copyright infringement. On December 24, 2015, the court consolidated the Cervantes and Weiss actions. The Company and the named officers and directors intend to defend themselves vigorously against these consolidated actions. On February 3, 2016, the court granted the Company’s motion to stay the consolidated actions. In light of, among other things, the early stage of the litigation, the Company is unable to predict the outcome of this matter and is unable to make a meaningful estimate of the amount or range of loss, if any, that could result from an unfavorable outcome. In addition, from time to time in the normal course of business, various other claims and litigation have been asserted or commenced against the Company. Due to uncertainties inherent in litigation and other claims, the Company can give no assurance that it will prevail in any such matters, which could subject the Company to significant liability for damages. Any claims or litigation, regardless of their success, could have an adverse effect on the Company’s consolidated results of operations or cash flows in the period the claims or litigation are resolved. As of September 30, 2016 , the Company does not believe that there are any material litigation exposures relating to these other claims.

Basis of Presentation and Sum19

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Consolidation	Basis of Consolidation The consolidated financial statements include the accounts of Etsy and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and judgments 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. The accounting estimates that require management’s most difficult and subjective judgments include revenue recognition, income taxes, website development costs and internal-use software, purchase price allocations for business combinations, valuation of goodwill and intangible assets, leases and stock-based compensation. The Company evaluates its estimates and judgments on an ongoing basis and revises them when necessary. Actual results may differ from the original or revised estimates.
Income Tax	Income Taxes The Company's income tax provision for interim periods is determined using an estimate of its annual effective tax rate adjusted for discrete items, if any, for relevant interim periods. The Company updates its estimate of the annual effective tax rate each quarter and makes cumulative adjustments if its estimated annual tax rate changes. The Company's quarterly tax provision and quarterly estimate of its annual effective tax rate are subject to significant variations due to several factors, including variability in predicting its pretax and taxable income and the mix of jurisdictions to which those relate, changes of expenses or losses for which tax benefits are not recognized and changes in the laws, regulations and administrative practices of the jurisdictions in which the Company operates.
Recently Issued and Recently Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or FASB, issued an accounting standards update that replaces existing revenue recognition guidance. The new guidance is effective for the annual and interim periods beginning after December 15, 2017. Among other things, the updated guidance requires companies to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2014, the FASB issued an accounting standard update under which management will be required to assess an entity’s ability to continue as a going concern and provide related disclosures in certain circumstances. The new guidance is effective for annual and interim periods ending after December 15, 2016. The adoption of this guidance is not expected to have an impact on the Company’s consolidated financial statements or disclosures. In February 2016, the FASB issued an accounting standard update that requires a reporting entity to recognize right-of-use assets and lease liabilities on the balance sheet for operating leases to increase transparency and comparability. The new guidance is effective for annual and interim periods beginning after December 15, 2018, and early adoption is permitted. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In March 2016, the FASB issued an accounting standard update for share-based payment transactions that require a reporting entity to recognize excess tax benefits and deficiencies as income tax expense or benefit in the income statement. The new guidance is effective for annual and interim periods beginning after December 15, 2016, and early adoption is permitted for financial statements as of the beginning of an interim or annual reporting period. The Company will adopt this standard in the first quarter of 2017 and is currently evaluating the effect the guidance will have on its consolidated financial statements. In August 2016, the FASB issued an accounting standard update to clarify how certain cash receipts and payments are presented and classified in the statement of cash flows. The new guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted for financial statements as of the beginning of an interim or annual reporting period. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. In October 2016, the FASB issued an accounting standard update to align the recognition of income tax consequences for intra-entity transfers of assets other than inventory with International Financial Reporting Standards.The new guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted for financial statements as of the beginning of an annual reporting period. The Company is currently evaluating the effect the guidance will have on its consolidated financial statements. Recently Adopted Accounting Pronouncements In April 2015, the FASB issued an accounting standard under which customers will apply the same criteria as vendors to determine whether a cloud computing arrangement contains a software license or is solely a service contract. The new standard is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no material impact to the current period consolidated financial statements. In August 2015, the FASB issued an accounting standard update to address the presentation and subsequent measurement of debt issuance costs related to line-of-credit arrangements. The guidance affirms the Company's treatment of such costs, which is to defer and present the debt issuance costs as an asset and subsequently amortize the costs over the term of the line-of-credit arrangement. The new standard is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no impact to the current period consolidated financial statements. In September 2015, the FASB issued an accounting standard update that eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The new guidance is effective for annual and interim periods beginning after December 15, 2015. The Company has adopted this guidance in the first quarter of 2016 noting no impact to the current period consolidated financial statements.

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The below table summarizes the components of the Blackbird purchase price and allocation of the purchase price at fair value (in thousands): Cash paid $ 8,050 Common shares 6,966 Total purchase consideration $ 15,016 Working capital $ 81 Developed technology 7,500 Goodwill 9,407 Deferred tax liability (1,972 ) Net assets acquired $ 15,016
Business Acquisition, Pro Forma Information	The unaudited pro forma financial information is presented in the table below for the three and nine months ended September 30, 2015 and 2016 (in thousands except per share amounts): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Revenue $ 65,725 $ 87,835 $ 185,691 $ 255,577 Net loss (10,472 ) (3,753 ) (57,336 ) (14,235 ) Basic and diluted net loss per share (0.09 ) (0.03 ) (0.68 ) (0.13 )

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Black-Scholes Valuation Assumptions Used to Determine Fair Value of Options Granted	The fair value of options granted in each year using the Black-Scholes pricing model has been based on the following assumptions: Three Months Ended Nine Months Ended 2015 2016 2015 2016 Volatility 44.1% - 44.7% 39.6% 40.4% - 45.0% 39.6% - 44.6% Risk-free interest rate 1.7% - 1.9% 1.1% - 1.5% 1.3% - 1.9% 1.1% - 1.9% Expected term (in years) 6.0 - 6.1 6.3 5.5 - 6.1 5.5 - 6.3 Dividend rate —% —% —% —%
Summary of Stock Option Activity	The following table summarizes the activity for the Company's options: Shares Weighted-Average Exercise Price Weighted-Average Remaining Contract Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2015 11,068,859 $ 6.94 Granted 1,478,569 8.95 Exercised (1,961,245 ) 3.98 Forfeited/Canceled (873,143 ) 9.50 Outstanding at September 30, 2016 9,713,040 7.61 6.60 $ 68,001,717 Total exercisable at September 30, 2016 6,563,414 5.95 5.66 56,041,779 Total vested and expected to vest at September 30, 2016 9,523,368 7.54 6.56 67,355,632
Summary of Intrinsic Value of Options Exercised and Fair Value of Awards Vested	The following table summarizes the weighted average grant date fair value of options granted, intrinsic value of options exercised and fair value of awards vested in the the three and nine months ended September 30, 2015 and 2016 : Three Months Ended Nine Months Ended 2015 2016 2015 2016 Weighted average grant date fair value of options granted $ 6.70 $ 4.84 $ 7.07 $ 3.89 Intrinsic value of options exercised 1,363,740 8,129,031 12,043,023 14,239,206 Fair value of awards vested 2,231,820 1,702,647 5,824,711 7,911,377
Summary of Weighted Average Grant Date Fair Value of Options Granted	The following table summarizes the weighted average grant date fair value of options granted, intrinsic value of options exercised and fair value of awards vested in the the three and nine months ended September 30, 2015 and 2016 : Three Months Ended Nine Months Ended 2015 2016 2015 2016 Weighted average grant date fair value of options granted $ 6.70 $ 4.84 $ 7.07 $ 3.89 Intrinsic value of options exercised 1,363,740 8,129,031 12,043,023 14,239,206 Fair value of awards vested 2,231,820 1,702,647 5,824,711 7,911,377
Summary of Unvested RSU Activity	The following table summarizes the activity for the Company's unvested RSUs: Shares Weighted-Average Unvested at December 31, 2015 395,846 $ 13.70 Granted 2,769,633 9.82 Vested (152,888 ) 10.90 Forfeited/Canceled (160,348 ) 9.76 Unvested at September 30, 2016 2,852,243 10.31 Total expected to vest at September 30, 2016 2,630,522 10.39
Schedule of Stock-Based Compensation Expense	Total stock-based compensation expense included in the consolidated statements of operations is as follows (in thousands): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Cost of revenue $ 149 $ 288 $ 681 $ 738 Marketing 120 229 349 628 Product development 756 1,234 1,981 3,117 General and administrative 1,898 2,334 6,706 7,107 Total stock-based compensation expense $ 2,923 $ 4,085 $ 9,717 $ 11,590

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Major Categories of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following are the major categories of assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 and September 30, 2016 (in thousands): As of December 31, 2015 Level 1 Level 2 Level 3 Total Asset Cash equivalents: Money market funds $ 212,390 $ — $ — $ 212,390 U.S. Government bills 3 — — 3 212,393 — — 212,393 Short-term investments: U.S. Government and agency bills 21,620 — — 21,620 $ 234,013 $ — $ — $ 234,013 Liability Acquisition–related contingent consideration classified as liability $ — $ — $ 2,357 $ 2,357 $ — $ — $ 2,357 $ 2,357 As of September 30, 2016 Level 1 Level 2 Level 3 Total Asset Cash equivalents: Money market funds $ 105,160 $ — $ — $ 105,160 U.S. Government bills 7,300 — — 7,300 112,460 — — 112,460 Short-term investments: Commercial paper — 5,999 — 5,999 Corporate bonds — 50,621 — 50,621 U.S. Government and agency bills 25,718 — — 25,718 25,718 56,620 — 82,338 $ 138,178 $ 56,620 $ — $ 194,798 Liability Acquisition–related contingent consideration classified as liability $ — $ — $ 2,315 $ 2,315 $ — $ — $ 2,315 $ 2,315
Reconciliation of the Beginning and Ending Balances for Liabilities Measured at Fair Value using Significant Unobservable Inputs	The table below provides a reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs (Level 3) (in thousands): Nine Months Ended Balance at beginning of period $ 2,357 Acquired — Changes to liability-classified stock awards 1,900 Settled — Conversion of liability-classified restricted shares upon vesting (1,942 ) Balance at end of period $ 2,315

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Cost and Fair Value of Available-for-sale Securities	The cost and fair value of available-for-sale securities were as follows as of the dates indicated (in thousands): Cost Gross Gross Fair Value December 31, 2015 U.S. Government and agency bills $ 21,636 $ (16 ) $ — $ 21,620 $ 21,636 $ (16 ) $ — $ 21,620 September 30, 2016 Commercial paper $ 5,999 $ — $ — $ 5,999 Corporate bonds 50,610 (3 ) 14 50,621 U.S. Government and agency bills 25,703 — 15 25,718 $ 82,312 $ (3 ) $ 29 $ 82,338

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table summarizes the changes in the carrying amount of goodwill for the period indicated (in thousands): Nine Months Ended Balance as of the beginning of the period $ 27,752 Acquisitions (1) 9,407 Foreign currency translation 606 Balance as of the end of the period $ 37,765 (1) The Company notes the purchase price allocation for the acquisition of Blackbird is preliminary and the resulting goodwill is subject to change based on finalization of the valuation of the business.
Finite-lived Intangible Assets Amortization Expenses	At December 31, 2015 and September 30, 2016 , the gross book value and accumulated amortization of intangible assets were as follows (in thousands): As of December 31, 2015 As of September 30, 2016 Gross book Accumulated Net book Gross book Accumulated Net book Trademarks $ 822 $ (427 ) $ 395 $ 839 $ (643 ) $ 196 Technology (1) 3,882 (2,340 ) 1,542 11,419 (3,303 ) 8,116 Customer relationships 1,959 (1,024 ) 935 1,997 (1,537 ) 460 Intangible assets, net $ 6,663 $ (3,791 ) $ 2,872 $ 14,255 $ (5,483 ) $ 8,772 (1) The Company notes the purchase price allocation for the acquisition of Blackbird is preliminary and gross intangible and related accumulated amortization balances are subject to change based on finalization of the valuation of the business.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Based on amounts recorded at September 30, 2016 , the Company will recognize intangible asset amortization expense for the three months ending December 31, 2016 and years ending December 31, 2017, 2018, 2019 and thereafter as follows (in thousands): 2016 $ 1,136 2017 3,365 2018 2,500 2019 1,771 Thereafter — Total amortization expense $ 8,772

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule of Calculation of Basic and Diluted Net (Loss) Income Per Share	The following table presents the calculation of basic and diluted net loss per share for periods presented (in thousands, except share and per share data): Three Months Ended Nine Months Ended 2015 2016 2015 2016 Net loss $ (6,891 ) $ (2,399 ) $ (49,831 ) $ (8,518 ) Basic and diluted shares: Weighted average common shares outstanding 111,329,917 113,757,212 84,195,227 112,980,639 Net loss per share attributable to common stockholders: Basic and diluted net loss per share applicable to common stockholders $ (0.06 ) $ (0.02 ) $ (0.59 ) $ (0.08 )
Schedule of Anti-Dilutive Securities Excluded from Computation of Earnings Per Share	The following potential common shares were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented: Three Months Ended Nine Months Ended 2015 2016 2015 2016 Stock options 11,904,577 10,364,872 11,914,369 10,890,258 Restricted stock units 148,188 2,358,365 60,204 1,718,766 Warrants 203,030 — 203,030 44,677 Convertible preferred stock — — 21,731,703 — Total anti-dilutive securities 12,255,795 12,723,237 33,909,306 12,653,701

Segment and Geographic Inform26

Segment and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Area	The following table summarizes revenue by geographic area (in thousands): Three Months Ended Nine Months Ended 2015 2016 2015 2016 United States $ 51,593 $ 66,204 $ 145,326 $ 194,018 International 14,103 21,358 40,278 60,740 Revenue $ 65,696 $ 87,562 $ 185,604 $ 254,758

Basis of Presentation and Sum27

Basis of Presentation and Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	Apr. 21, 2015USD ($)$ / sharesshares	Mar. 25, 2015	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from initial public offering | $			$ 0	$ 199,467
Reverse stock split conversion ratio		0.5
IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares) | shares	13,333,333
Share price (in dollars per share) | $ / shares	$ 16
Proceeds from initial public offering | $	$ 194,400
Underwriting discount | $	13,900
Other offering expense | $	$ 5,100
Sale of stock by stockholders (in shares) | shares	5,833,332
Conversion of preferred stock warrants into common stock warrants (in shares) | shares	203,030
Convertible preferred stock | IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion of convertible preferred stock into common stock (in shares) | shares	53,448,243

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Thousands	Sep. 19, 2016	Nov. 03, 2016	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015
Business Acquisition [Line Items]
Amortization of intangible assets				$ 1,600	$ 1,700
Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Common stock, value, outstanding	$ 32,500
Consideration transferred	15,016
Payments to acquire businesses	$ 8,050
Stock issued during period (in shares)	184,230
Stock issued during period, value	$ 2,500
Stock option vesting period	3 years
Contractual obligation payment	$ 8,800
Amortization of intangible assets			$ 100	0
Net loss			$ (300)	(800)
Blackbird Technologies, Inc. | Common Stock
Business Acquisition [Line Items]
Number of shares issued (in shares)	513,304
Fair value of shares issued	$ 6,900
Scenario, Forecast | Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Stock issued during period (in shares)		460,575
Stock issued during period, value		$ 6,200
Stock option vesting period		3 years
Technology-Based Intangible Assets | Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Intangible asset, useful life	3 years
General and administrative | Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Acquisition related costs				$ 500

Business Combination - Schedule

Business Combination - Schedule of Business Acquisition (Details) - USD ($) $ in Thousands	Sep. 19, 2016	Sep. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill		$ 37,765	$ 27,752
Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Cash paid	$ 8,050
Total purchase consideration	15,016
Working capital	81
Goodwill	9,407
Deferred tax liability	(1,972)
Net assets acquired	15,016
Blackbird Technologies, Inc. | Common Stock
Business Acquisition [Line Items]
Common shares	6,966
Technology-Based Intangible Assets | Blackbird Technologies, Inc.
Business Acquisition [Line Items]
Developed technology	$ 7,500

Business Combination - Pro Form

Business Combination - Pro Forma Schedule (Details) - Blackbird Technologies, Inc. - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Business Acquisition [Line Items]
Revenue	$ 87,835	$ 65,725	$ 255,577	$ 185,691
Net loss	$ (3,753)	$ (10,472)	$ (14,235)	$ (57,336)
Basic and diluted net loss per share (in dollars per share)	$ (0.03)	$ (0.09)	$ (0.13)	$ (0.68)

Debt (Details)

Debt (Details) - Revolving Credit Facility	9 Months Ended
	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2015USD ($)	May 31, 2014USD ($)
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity			$ 50,000,000	$ 35,000,000
Line of credit, maximum available borrowing capacity	$ 50,000,000
Line of credit, maximum available borrowing capacity, minimum increment of increase	$ 10,000,000
Total leverage ratio	3.50
Outstanding borrowings	$ 0
Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	0.50%
One-Month London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	1.00%
One-Month London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	1.00%
One-Month London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	1.25%
Base Rate | Minimum
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	0.00%
Base Rate | Maximum
Debt Instrument [Line Items]
Line of credit, basis spread on variable interest rate	0.25%
Letter of Credit
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity		$ 10,000,000
Bridge Loan
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity		$ 15,000,000

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($) $ in Thousands	Jan. 04, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation		$ 15,100		$ 15,100
Stock-based compensation expense—acquisitions		1,100	$ 700	$ 2,582	$ 3,158
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation, period of recognition				2 years 6 months 15 days
Stock options | Current employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period				48 months
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation, period of recognition				3 years 5 months 5 days
Total unrecognized compensation		$ 27,700		$ 27,700
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of additional shares issued annually (in shares)	2,814,083			7,050,000
Percentage of outstanding stock				5.00%
Shares reserved for future issuance (in shares)		14,100,000		14,100,000
Number of shares authorized (in shares)		17,549,262		17,549,262
Number of shares available for grant (in shares)		14,028,358		14,028,358
2015 Equity Incentive Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term for options				10 years
Stock option vesting period				4 years
Stock option requisite service period				4 years
2015 Equity Incentive Plan | Stock options | Newly-hired employee | Vest 25% after first year of service
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting rights (percentage)				25.00%
2015 Equity Incentive Plan | Stock options | Newly-hired employee | Vest ratably over 48 month period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period				36 months
2015 Equity Incentive Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period				4 years
2015 Equity Incentive Plan | RSUs | Newly-hired employee | Vest 25% after first year of service
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting rights (percentage)				25.00%
2015 Equity Incentive Plan | RSUs | Newly-hired employee | Vest ratably over 48 month period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period				3 years
2015 Equity Incentive Plan | RSUs | Current employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period				4 years
2006 Plan Eligible for 2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (in shares)		12,653,075		12,653,075

Stock-based Compensation - Fair

Stock-based Compensation - Fair Value of Options Granted Using the Black-Scholes Pricing Model (Details) - Stock options	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum		44.10%	39.60%	40.40%
Expected volatility rate	39.60%
Volatility, maximum		44.70%	44.60%	45.00%
Risk-free interest rate, minimum	1.10%	1.70%	1.10%	1.30%
Risk-free interest rate, maximum	1.50%	1.90%	1.90%	1.90%
Expected term (in years)	6 years 3 months 18 days
Dividend rate	0.00%	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years	5 years 6 months	5 years 6 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years 1 month 6 days	6 years 3 months 18 days	6 years 1 month 6 days

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Shares
Outstanding, beginning balance (in shares) | shares	11,068,859
Granted (in shares) | shares	1,478,569
Exercised (in shares) | shares	(1,961,245)
Forfeited/Canceled (in shares) | shares	(873,143)
Outstanding, ending balance (in shares) | shares	9,713,040
Total exercisable at September 30, 2016 (in shares) | shares	6,563,414
Total vested and expected to vest at September 30, 2016 (in shares) | shares	9,523,368
Weighted-Average Exercise Price
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 6.94
Granted (in dollars per share) | $ / shares	8.95
Exercised (in dollars per share) | $ / shares	3.98
Forfeited/Canceled (in dollars per share) | $ / shares	9.50
Outstanding, ending balance (in dollars per share) | $ / shares	7.61
Total exercisable at September 30, 2016 (in dollars per share) | $ / shares	5.95
Total vested and expected to vest at September 30, 2016 (in dollars per share) | $ / shares	$ 7.54
Weighted-Average Remaining Contract Term (in years)
Outstanding at September 30, 2016, Weighted-Average Remaining Contract Term	6 years 7 months 6 days
Total exercisable at September 30, 2016, Weighted-Average Remaining Contract Term	5 years 7 months 28 days
Total vested and expected to vest at September 30, 2016, Weighted-Average Remaining Contract Term	6 years 6 months 22 days
Aggregate Intrinsic Value
Outstanding at September 30, 2016, Aggregate Intrinsic Value | $	$ 68,001,717
Total exercisable at September 30, 2016, Aggregate Intrinsic Value | $	56,041,779
Total vested and expected to vest at September 30, 2016, Aggregate Intrinsic Value | $	$ 67,355,632

Stock-based Compensation - Weig

Stock-based Compensation - Weighted Average Grant Date Fair Value of Options Granted, Intrinsic Value of Options Exercised and Fair Value of Awards Vested (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average grant date fair value of options (in dollars per share)	$ 4.84	$ 6.70	$ 3.89	$ 7.07
Intrinsic value of options exercised	$ 8,129,031	$ 1,363,740	$ 14,239,206	$ 12,043,023
Fair value of awards vested	$ 1,702,647	$ 2,231,820	$ 7,911,377	$ 5,824,711

Stock-based Compensation - Su36

Stock-based Compensation - Summary of Unvested RSUs (Details) - RSUs	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Shares
Unvested at December 31, 2015 (in shares) | shares	395,846
Granted (in shares) | shares	2,769,633
Vested (in shares) | shares	(152,888)
Forfeited/Cancelled (in shares) | shares	(160,348)
Unvested at September 30, 2016 (in shares) | shares	2,852,243
Total expected to vest at September 30, 2016 (in shares) | shares	2,630,522
Weighted-Average Grant Date Fair Value
Unvested at December 31, 2015 (in dollars per share) | $ / shares	$ 13.70
Granted (in dollars per share) | $ / shares	9.82
Vested (in dollars per share) | $ / shares	10.90
Forfeited/Cancelled (in dollars per share) | $ / shares	9.76
Unvested at September 30, 2016 (in dollars per share) | $ / shares	10.31
Total expected to vest at September 30, 2016 (in dollars per share) | $ / shares	$ 10.39

Stock-based Compensation - Allo

Stock-based Compensation - Allocated Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4,085	$ 2,923	$ 11,590	$ 9,717
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	288	149	738	681
Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	229	120	628	349
Product development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,234	756	3,117	1,981
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,334	$ 1,898	$ 7,107	$ 6,706

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015	Jan. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Deferred income tax expense (benefit)	$ 3,000	$ 12,200
Deferred costs	56,300	56,300
Deferred tax charge—current	17,132	17,132	$ 17,132
Deferred tax charge—net of current portion	39,169	39,169	51,396
Global Corporate Structure [Member]
Deferred Tax Assets and Liabilities [Line Items]
Deferred tax liability for gain in revised corporate structure transaction				$ 66,000
Deferred tax assets				66,000
Deferred income tax expense (benefit)	2,300	9,400
Unrecognized Tax Benefit [Member]
Deferred Tax Assets and Liabilities [Line Items]
Deferred tax assets				$ 19,700
Decrease in unrecognized tax benefits		1,300
Unrecognized tax benefits	23,500	23,500	$ 22,200
Unrecognized tax benefits that would impact effective tax rate favorably	10,600	10,600
Deferred income tax expense (benefit)	$ 700	$ 2,800

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Major Categories of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 112,460	$ 212,393
Short-term investments	82,338
Asset	194,798	234,013
Liability	2,315	2,357
Acquisition–related contingent consideration classified as liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability	2,315	2,357
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	105,160	212,390
U.S. Government bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	7,300	3
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	5,999
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	50,621
U.S. Government and agency bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	25,718	21,620
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	112,460	212,393
Short-term investments	25,718
Asset	138,178	234,013
Liability	0	0
Level 1 | Acquisition–related contingent consideration classified as liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability	0	0
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	105,160	212,390
Level 1 | U.S. Government bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	7,300	3
Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 1 | U.S. Government and agency bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	25,718	21,620
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	56,620
Asset	56,620	0
Liability	0	0
Level 2 | Acquisition–related contingent consideration classified as liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability	0	0
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | U.S. Government bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	5,999
Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	50,621
Level 2 | U.S. Government and agency bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0
Asset	0	0
Liability	2,315	2,357
Level 3 | Acquisition–related contingent consideration classified as liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability	2,315	2,357
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 3 | U.S. Government bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 3 | U.S. Government and agency bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 0	$ 0

Fair Value Measurements - Sch40

Fair Value Measurements - Schedule of Unobservable Inputs Reconciliation (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Reconciliation of Beginning and Ending Balances for the Liabilities Measured at Fair Value Using Significant Observable Inputs
Balance at beginning of period	$ 2,357
Acquired	0
Changes to liability-classified stock awards	1,900
Settled	0
Conversion of liability-classified restricted shares upon vesting	(1,942)
Balance at end of period	$ 2,315

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 82,312	$ 21,636
Gross Unrealized Holding Loss	(3)	(16)
Gross Unrealized Holding Gain	29	0
Fair Value	82,338	21,620
U.S. Government and agency bills
Schedule of Available-for-sale Securities [Line Items]
Cost	25,703	21,636
Gross Unrealized Holding Loss	0	(16)
Gross Unrealized Holding Gain	15	0
Fair Value	25,718	$ 21,620
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Cost	5,999
Gross Unrealized Holding Loss	0
Gross Unrealized Holding Gain	0
Fair Value	5,999
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Cost	50,610
Gross Unrealized Holding Loss	(3)
Gross Unrealized Holding Gain	14
Fair Value	$ 50,621

Goodwill and Intangible Asset42

Goodwill and Intangible Assets - Schedule of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Goodwill [Roll Forward]
Balance as of the beginning of the period	$ 27,752
Acquisitions	9,407
Foreign currency translation	606
Balance as of the end of the period	$ 37,765

Goodwill and Intangible Asset43

Goodwill and Intangible Assets - Accumulated Amortization Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Gross book value	$ 14,255	$ 6,663
Accumulated amortization	(5,483)	(3,791)
Total amortization expense	8,772	2,872
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross book value	839	822
Accumulated amortization	(643)	(427)
Total amortization expense	196	395
Technology-Based Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross book value	11,419	3,882
Accumulated amortization	(3,303)	(2,340)
Total amortization expense	8,116	1,542
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross book value	1,997	1,959
Accumulated amortization	(1,537)	(1,024)
Total amortization expense	$ 460	$ 935

Goodwill and Intangible Asset44

Goodwill and Intangible Assets - Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
2,016	$ 1,136
2,017	3,365
2,018	2,500
2,019	1,771
Thereafter	0
Total amortization expense	$ 8,772	$ 2,872

Goodwill and Intangible Asset45

Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 1.6	$ 1.7

Net Loss Per Share - Calculatio

Net Loss Per Share - Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net loss	$ (2,399)	$ (6,891)	$ (8,518)	$ (49,831)
Basic and diluted shares:
Weighted average common shares outstanding (in shares)	113,757,212	111,329,917	112,980,639	84,195,227
Net loss per share attributable to common stockholders:
Basic and diluted net loss per share applicable to common stockholders (in dollars per share)	$ (0.02)	$ (0.06)	$ (0.08)	$ (0.59)

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Shares Excluded from the Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share (in shares)	12,723,237	12,255,795	12,653,701	33,909,306
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share (in shares)	10,364,872	11,904,577	10,890,258	11,914,369
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share (in shares)	2,358,365	148,188	1,718,766	60,204
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share (in shares)	0	203,030	44,677	203,030
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share (in shares)	0	0	0	21,731,703

Segment and Geographic Inform48

Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue, Major Customer [Line Items]
Revenue	$ 87,562	$ 65,696	$ 254,758	$ 185,604
United States
Revenue, Major Customer [Line Items]
Revenue	66,204	51,593	194,018	145,326
International
Revenue, Major Customer [Line Items]
Revenue	$ 21,358	$ 14,103	$ 60,740	$ 40,278

Contingencies (Details)

Contingencies (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Non-Income Tax Obligations
Loss Contingencies [Line Items]
Non-income tax obligation reserve	$ 1.2	$ 2.6