Wayfair (W) 10-Q 8 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Entity Information [Line Items]
Entity Registrant Name	Wayfair Inc.
Entity Central Index Key	1,616,707
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
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
Class A common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		49,450,946
Class B common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		36,091,181

CONSOLIDATED AND CONDENSED BALA

CONSOLIDATED AND CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 208,344	$ 334,176
Short-term investments	84,471	51,895
Accounts receivable, net of allowance of $2,675 and $2,767 at September 30, 2016 and December 31, 2015, respectively	16,689	9,906
Inventories	19,188	19,900
Prepaid expenses and other current assets	87,417	76,446
Total current assets	416,109	492,323
Property and equipment, net	211,285	112,325
Goodwill and intangible assets, net	4,530	3,702
Long-term investments	41,718	79,883
Other noncurrent assets	10,477	6,348
Total assets	684,119	694,581
Current liabilities
Accounts payable	312,306	270,913
Accrued expenses	68,289	51,560
Deferred revenue	55,383	50,884
Other current liabilities	37,014	23,669
Total current liabilities	472,992	397,026
Lease financing obligation	28,900	0
Other liabilities	71,723	55,010
Total liabilities	573,615	452,036
Commitments and contingencies
Convertible preferred stock, $0.001 par value per share: 10,000,000 shares authorized and none issued at September 30, 2016 and December 31, 2015	0	0
Stockholders’ equity:
Additional paid-in capital	396,949	378,162
Accumulated deficit	(285,984)	(135,565)
Accumulated other comprehensive loss	(546)	(136)
Total stockholders’ equity	110,504	242,545
Total liabilities and stockholders’ equity	684,119	694,581
Class A common stock
Stockholders’ equity:
Common stock	49	46
Class B common stock
Stockholders’ equity:
Common stock	$ 36	$ 38

CONSOLIDATED AND CONDENSED BAL3

CONSOLIDATED AND CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable allowance for doubtful accounts	$ 2,675	$ 2,767
Convertible redeemable preferred units, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible redeemable preferred units, shares authorized (in shares)	10,000,000	10,000,000
Convertible redeemable preferred units, shares issued (in shares)	0	0
Class A common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares outstanding (in shares)	49,303,861	45,814,237
Common stock, shares issued (in shares)	49,303,861	45,814,237
Class B common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	164,000,000	164,000,000
Common stock, shares outstanding (in shares)	36,100,764	38,496,562
Common stock, shares issued (in shares)	36,100,764	38,496,562

CONSOLIDATED AND CONDENSED STAT

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net revenue	$ 861,525	$ 593,972	$ 2,395,801	$ 1,510,095
Cost of goods sold	659,864	452,586	1,826,570	1,145,073
Gross profit	201,661	141,386	569,231	365,022
Operating expenses:
Customer service and merchant fees	33,872	21,109	91,286	55,417
Advertising	101,333	70,711	293,436	190,249
Merchandising, marketing and sales	48,550	27,083	129,679	74,131
Operations, technology, general and administrative	79,526	41,120	207,289	110,581
Total operating expenses	263,281	160,023	721,690	430,378
Loss from operations	(61,620)	(18,637)	(152,459)	(65,356)
Interest (expense) income, net	(292)	325	791	897
Other income, net	889	2,746	1,804	2,542
Loss before income taxes	(61,023)	(15,566)	(149,864)	(61,917)
(Benefit from) provision for income taxes	(83)	(88)	555	31
Net loss	$ (60,940)	$ (15,478)	$ (150,419)	$ (61,948)
Net loss per share, basic and diluted (in dollars per share)	$ (0.72)	$ (0.18)	$ (1.77)	$ (0.74)
Weighted average number of common stock outstanding used in computing per share amounts, basic and diluted (in shares)	85,105	83,886	84,779	83,569

CONSOLIDATED AND CONDENSED STA5

CONSOLIDATED AND CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - 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	$ (60,940)	$ (15,478)	$ (150,419)	$ (61,948)
Other comprehensive loss:
Foreign currency translation adjustments	(240)	371	(875)	323
Net unrealized (loss) gain on available-for-sale investments	(163)	(67)	465	(69)
Comprehensive loss	$ (61,343)	$ (15,174)	$ (150,829)	$ (61,694)

CONSOLIDATED AND CONDENSED STA6

CONSOLIDATED AND CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities
Net loss	$ (150,419)	$ (61,948)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities
Depreciation and amortization	38,528	23,351
Equity based compensation	35,188	21,741
Gain on sale of a business	0	(2,997)
Other non-cash adjustments	(134)	1,395
Changes in operating assets and liabilities:
Accounts receivable	(6,773)	(3,832)
Inventories	716	(2,778)
Prepaid expenses and other current assets	(12,493)	(28,419)
Accounts payable and accrued expenses	53,443	60,340
Deferred revenue and other liabilities	33,556	37,927
Other assets	(2,292)	(25)
Net cash (used in) provided by operating activities	(10,680)	44,755
Cash flows from investing activities
Purchase of short-term and long-term investments	(76,458)	(141,309)
Sale and maturities of short-term investments	82,060	78,715
Purchase of property and equipment	(81,844)	(36,695)
Site and software development costs	(21,444)	(13,107)
Cash received from the sale of a business, net of cash sold	1,508	2,860
Other investing activities, net	(1,000)	302
Net cash used in investing activities	(97,178)	(109,234)
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(18,426)	(12,899)
Net proceeds from exercise of stock options	166	374
Net cash used in financing activities	(18,260)	(12,525)
Effect of exchange rate changes on cash and cash equivalents	286	(165)
Net decrease in cash and cash equivalents	(125,832)	(77,169)
Cash and cash equivalents
Beginning of period	334,176	355,859
End of period	208,344	278,690
Supplemental disclosure of non-cash investing activities
Purchase of property and equipment included in accounts payable and accrued expenses and in other liabilities	5,744	2,636
Construction costs capitalized under finance lease obligations	$ 29,726	$ 8,687

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Wayfair Inc. (the “Company”) is an e-commerce business offering visually inspiring browsing, compelling merchandising, easy product discovery and attractive prices for over seven million products from over 7,000 suppliers across five distinct brands—Wayfair, Joss & Main, AllModern, DwellStudio, and Birch Lane. In addition to generating net revenue through Direct Retail sales, which includes all sales generated primarily through the Company’s websites, mobile optimized websites, and mobile applications (“sites”), net revenue is also generated through sites operated by third parties and through third party advertising distribution providers that pay the Company based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company’s sites. The consolidated and condensed financial statements and other disclosures contained in this Quarterly Report on Form 10-Q are those of the Company. The consolidated and condensed balance sheet data as of December 31, 2015 was derived from audited financial statements. The accompanying consolidated and condensed balance sheet as of September 30, 2016 , the consolidated statements of operations, consolidated statements of comprehensive loss, and consolidated statements of cash flows for the periods ended September 30, 2016 and 2015 are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited consolidated financial statements and in the opinion of management, reflect all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2016 and statements of operations, comprehensive loss, and cash flows for the periods ended September 30, 2016 and 2015 . The financial data and the other information disclosed in these notes to the consolidated and condensed financial statements related to these periods are unaudited. The consolidated and condensed statements of operations, comprehensive loss, and cash flows for the period ended September 30, 2016 are not necessarily indicative of the results of operations and cash flows that may be expected for the year ending December 31, 2016 , or for any other period.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The Company has identified the significant accounting policies that are critical to understanding its business and results of operations. The Company believes that there have been no significant changes during the nine months ended September 30, 2016 to the items disclosed in Note 2, Summary of Significant Accounting Policies , in the Notes to the Consolidated Financial Statements included in Part II, Item 8, Financial Statements and Supplementary Data , of the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 other than those noted below. Marketable Securities The Company classifies its marketable securities as "available-for-sale" securities. Available-for-sale securities are classified as short term investments and long-term investments on the consolidated balance sheets and are carried at fair value. Unrealized gains and losses on available-for-sale securities that are considered temporary are recorded, net of taxes, in the "Accumulated other comprehensive loss" caption of the Company’s consolidated balance sheets. Unrealized losses, excluding losses related to the credit rating of the security (credit losses), on available-for-sale securities that are considered other-than-temporary but relate to securities that the Company (i) does not intend to sell and (ii) will not be required to sell below cost are also recorded, net of taxes, in "Accumulated other comprehensive loss." Further, the Company does not believe it will be required to sell such securities below cost. Therefore, the only other-than-temporary losses the Company records in "Other income, net" in its consolidated statements of operations are related to credit losses. As of September 30, 2016 , the Company’s available-for-sale securities consisted of investment securities. The maturities of the Company’s long-term marketable securities generally range from one to three years. As of September 30, 2016 , the Company’s available-for-sale securities primarily consisted of corporate bonds and other government obligations that are priced at fair value. The cost basis of a marketable security sold is determined by the Company using the specific identification method. Property and Equipment Property and equipment are stated at cost, net of depreciation and amortization. Depreciation and amortization on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets as follows: Class Range of Life (In Years) Furniture and computer equipment 3 to 7 Site and software development costs 2 Leasehold improvements Lesser of useful life or lease term Building 30 Revenue Recognition The Company generates net revenue through product sales generated primarily through the sites of the Company's five distinct brands and through sites operated by third parties. The Company recognizes revenue for product sales generated through the sites of the Company's five distinct brands and through sites operated by third parties only when the following four criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company recognizes net revenue from sales of its products upon delivery to the customer. The Company records product revenue at the gross amount as the Company is the primary obligor with the customer and provides the primary customer service for all products sold, has latitude in establishing price and selecting products sold, has discretion in selecting suppliers of products sold, maintains inventory risk from shipment through delivery date and upon accepting returns, and has credit risk. Net revenue includes shipping costs charged to the customer and is recorded net of taxes collected from customers, which are remitted to governmental authorities. Cash discounts, returns and rebates are deducted from gross revenue in determining net revenue. In addition, the Company defers revenue when cash is collected from its customer prior to the satisfaction of the revenue recognition criteria. The Company maintains a membership rewards program that allows enrolled customers to earn points which can be redeemed for future purchases. The Company defers a portion of its revenue associated with rewards that are ultimately expected to be redeemed prior to expiration. The Company also earns revenue through third-party advertisers that pay based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company's sites. Revenue earned under these arrangements is included in net revenue and is recognized in the period in which the click, action, or impression occurs.

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	Marketable Securities and Fair Value Measurements Marketable Securities As of September 30, 2016 and December 31, 2015 , all of the Company’s marketable securities were classified as available-for-sale and their estimated fair values were $101.2 million and $96.8 million , respectively. We periodically review our available-for-sale securities for other-than-temporary impairment. We consider factors such as the duration, severity and the reason for the decline in value, the potential recovery period, and our intent to sell. As of September 30, 2016 , the Company’s available-for-sale securities primarily consisted of corporate bonds and other government obligations that are priced at fair value. During the three and nine months ended September 30, 2016 and 2015 , we did not recognize any other-than-temporary impairment loss. The maturities of the Company’s long-term marketable securities generally range from one to three years. The cost basis of a marketable security sold is determined by the Company using the specific identification method. During the three and nine months ended September 30, 2016 and 2015 , we did not have any realized gains or losses. The following tables present details of the Company’s marketable securities as of September 30, 2016 and December 31, 2015 (in thousands): September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 54,327 $ 21 $ (10 ) $ 54,338 Commercial paper 5,135 — (2 ) 5,133 Long-term: Investment securities 41,564 163 (9 ) 41,718 Total $ 101,026 $ 184 $ (21 ) $ 101,189 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 16,908 $ — $ (13 ) $ 16,895 Long-term: Investment securities 80,172 2 (291 ) 79,883 Total $ 97,080 $ 2 $ (304 ) $ 96,778 Fair Value Measurements The Company's financial assets and liabilities are measured at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The three levels of inputs used to measure fair value are as follows: ▪ Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities ▪ Level 2—Unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable or can be corroborated by observable market data for substantially the full-term of the asset or liability ▪ Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the asset or liability This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The Company measures its cash equivalents and short-term and long-term investments at fair value. The Company classifies its cash equivalents and restricted cash within Level 1 because the Company values these investments using quoted market prices. The fair value of the Company's Level 1 financial assets is based on quoted market prices of the identical underlying security. The Company classifies short-term and long-term investments within Level 2 because unadjusted quoted prices for identical or similar assets in markets are not active. The Company does not have any assets or liabilities classified as Level 3 financial assets. The following tables set forth the fair value of the Company’s financial assets measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 based on the three-tier value hierarchy (in thousands): September 30, 2016 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 88,265 $ — $ — $ 88,265 Commercial paper — 5,133 — 5,133 Short-term investments: Certificates of deposit 25,000 — — 25,000 Investment securities — 54,338 — 54,338 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 41,718 — 41,718 Total $ 118,265 $ 101,189 $ — $ 219,454 December 31, 2015 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 267,300 $ — $ — $ 267,300 Short-term investments: Certificates of deposit 35,000 — — 35,000 Investment securities — 16,895 — 16,895 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 79,883 — 79,883 Total $ 307,300 $ 96,778 $ — $ 404,078

Intangible Assets and Goodwill

Intangible Assets and Goodwill	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill The following table summarizes intangible assets as of September 30, 2016 and December 31, 2015 (in thousands): Weighted - Average Amortization Period (Years) September 30, 2016 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (1,203 ) $ 697 Technology 3 1,453 (40 ) $ 1,413 Customer relationships 5 1,300 (823 ) 477 Other intangibles 3 373 (354 ) 19 Total $ 5,026 $ (2,420 ) $ 2,606 Weighted - Average Amortization Period (Years) December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (918 ) $ 982 Customer relationships 5 1,300 (628 ) 672 Non-compete agreements 3 - 5 100 (81 ) 19 Other intangibles 3 373 (270 ) 103 Domain names 5 2,687 (2,685 ) 2 Total $ 6,360 $ (4,582 ) $ 1,778 Amortization expense related to intangible assets was $0.2 million for the three months ended September 30, 2016 and 2015 , and $0.6 million and $0.7 million for the nine months ended September 30, 2016 and 2015 , respectively. Goodwill as of September 30, 2016 was $1.9 million , unchanged from December 31, 2015 .

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The following table summarizes property and equipment, net as of September 30, 2016 and December 31, 2015 (in thousands): September 30, December 31, Furniture and computer equipment $ 127,565 $ 68,416 Site and software development costs 68,906 50,907 Leasehold improvements 58,322 29,315 Construction in progress 23,364 27,563 Building (leased - Note 6) 29,856 — 308,013 176,201 Less accumulated depreciation and amortization (96,728 ) (63,876 ) Property and equipment, net $ 211,285 $ 112,325 Property and equipment depreciation and amortization expense was $15.2 million and $9.0 million for the three months ended September 30, 2016 and 2015 , respectively, and $37.9 million and $22.7 million for the nine months ended September 30, 2016 and 2015 , respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company leases office and warehouse spaces under non-cancelable leases. These leases expire at various dates through 2027 and include discounted rental periods and fixed escalation clauses, which are amortized straight-line over the terms of the lease. Rent expense under operating leases was $9.1 million and $3.8 million in the three months ended September 30, 2016 and 2015 , respectively, and $23.9 million and $12.3 million in the nine months ended September 30, 2016 and 2015 , respectively. The Company has issued letters of credit for approximately $10.6 million and $5.9 million as security for these lease agreements as of September 30, 2016 and December 31, 2015 , respectively. The Company has entered into additional leases throughout the United States ("U.S.") and Europe subsequent to December 31, 2015, where the future minimum rental commitments under non-cancelable leases with initial or remaining terms in excess of one year are $ 358.5 million in the aggregate. The Company establishes assets and liabilities for the estimated construction costs incurred under lease arrangements where the Company is considered the owner for accounting purposes only, or build-to-suit leases, to the extent the Company is involved in the construction of structural improvements or takes construction risk prior to commencement of a lease. Upon occupancy of facilities under build-to-suit leases, the Company assesses whether these arrangements qualify for sales recognition under the sale-leaseback accounting guidance. If the Company continues to be the deemed owner, the facilities are accounted for as financing leases. The construction of one warehouse lease arrangement was completed during the three months ended June 30, 2016, and because the Company concluded it had a letter of credit of $1.2 million , the Company did not meet the sale-leaseback criteria for derecognition of the building asset and liability. Therefore, the lease was accounted for as a financing obligation and $28.9 million was recorded in "Lease financing obligation" in the Company’s unaudited consolidated and condensed balance sheets. The monthly rent payments made to the lessor under the lease agreement are recorded in the Company’s financial statements as land lease expense and principal and interest on the financing obligation. Interest expense on the lease financing obligation reflects the portion of the Company's monthly lease payments that is allocated to interest expense. For the three and nine months ended September 30, 2016 , land lease expense was $0.1 million and interest expense on lease financing obligation was $0.8 million . As of September 30, 2016 , future minimum commitments related to the financing obligation were $2.1 million and $12.0 million for principal and interest, respectively, through September 30, 2021. Collection of Sales or Other Similar Taxes Based on the location of the Company’s current operations, it collects and remits sales tax in Kentucky, Massachusetts, New York, Utah, California, Illinois, Texas, New Jersey, and North Carolina. The Company does not currently collect sales or other similar taxes for the sale of goods in states where no obligation to collect these taxes is required under applicable law. Several states have presented the Company with assessments, alleging that it is required to collect and remit sales or other similar taxes. The aggregate amount of claims from these states, not including taxes allegedly owed for periods subsequent to such assessments or interest and penalties after the date the Company last received such assessments, is approximately $28.2 million . The Company does not believe that it was obligated to collect and remit such taxes, and intends to vigorously defend its position. At this time, the Company believes a loss is not probable and therefore has not recorded a liability; however, no assurance can be given as to the outcome of these assessments. Legal Matters In September 2016, a putative class action complaint was filed against the Company in the Superior Court of the province of Quebec (Naomi Zouzout v. Wayfair LLC, Case No. PQ 500-06-000809-166) by an individual on behalf of herself and on behalf of all other similarly situated individuals alleging violations of various Canadian consumer protection statutes. Among other remedies, this lawsuit seeks compensatory and punitive money damages, costs, and various fees. The Company intends to defend the lawsuit vigorously. At this time, based on available information regarding this litigation, the Company is unable to reasonably assess the ultimate outcome of this case or determine an estimate, or a range of estimates, of potential losses. From time to time the Company is involved in claims that arise during the ordinary course of business. Although the results of litigation and claims cannot be predicted with certainty, the Company does not currently believe that the outcome of any of these other legal matters will have a material adverse effect on the Company's results of operation or financial condition. Regardless of the outcome, litigation can be costly and time consuming, as it can divert management’s attention from important business matters and initiatives, negatively impacting the Company's overall operations. In addition, the Company may also find itself at greater risk to outside party claims as it increases its operations in jurisdictions where the laws with respect to the potential liability of online retailers are uncertain, unfavorable, or unclear.

Equity-Based Compensation

Equity-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity-Based Compensation	Equity-Based Compensation In 2010, the Company established an equity incentive plan and, in 2011, the plan was amended and restated as the Wayfair LLC Amended and Restated 2010 Common Unit Plan (the “2010 Plan”). The 2010 Plan was administered by the board of directors of Wayfair LLC and provided for the issuance of common option units, restricted common units (all common units), and deferred units, which currently represent Class A or Class B common stock of the Company. In connection with the IPO, the board of directors of the Company adopted the 2014 Incentive Award Plan ("2014 Plan") to grant cash and equity incentive awards to eligible service providers in order to attract, motivate and retain the talent for which the Company competes. The 2014 Plan is administered by the board of directors of the Company with respect to awards to non-employee directors and by the compensation committee with respect to other participants and provides for the issuance of stock options, SARs, restricted stock, restricted stock units ("RSUs"), performance shares, stock payments, cash payments, dividend awards and other incentives. The 2014 Plan authorizes up to 8,603,066 shares of Class A common stock to be issued, of which RSUs for 5,949,611 shares had been issued as of September 30, 2016 . Shares or RSUs forfeited, withheld for minimum statutory tax obligations, and unexercised stock option lapses from the 2010 and 2014 Plans are available for grants of awards under the 2014 Plan. In addition, on the first day of each calendar year beginning January 1, 2016 and ending on and including January 1, 2024, the shares available for future grant are increased in accordance with the 2014 Plan. The following table presents activity relating to stock options for the nine months ended September 30, 2016 : Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Outstanding at December 31, 2015 279,591 $ 2.98 5.5 Options exercised (55,827 ) $ 2.98 Options forfeited/canceled (176 ) $ 3.42 Outstanding at September 30, 2016 223,588 $ 2.98 4.7 Exercisable at September 30, 2016 223,588 $ 2.98 4.7 Intrinsic value of stock options exercised was $2.1 million for the nine months ended September 30, 2016 . Aggregate intrinsic value of stock options outstanding and currently exercisable is $8.1 million . All stock options were fully vested at September 30, 2016 . The following table presents activity relating to restricted common stock for the nine months ended September 30, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 1,993 $ 4.75 Restricted stock granted 60,000 $ 44.34 Restricted stock vested (1,993 ) $ 4.75 Unvested at September 30, 2016 60,000 $ 39.37 Expected to vest at September 30, 2016 49,171 $ 39.37 The intrinsic value of restricted common stock vested was less than $0.1 million for the nine months ended September 30, 2016 . Aggregate intrinsic value of restricted common stock unvested is $2.4 million as of September 30, 2016 . Unrecognized equity based compensation expense related to restricted common stock expected to vest over time is $1.8 million with a weighted average remaining vesting term of 2.2 years as of September 30, 2016 . The following table presents activity relating to RSUs for the nine months ended September 30, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 5,607,867 $ 28.30 RSUs granted 2,851,452 $ 39.65 RSUs vested (1,431,327 ) $ 25.14 RSUs forfeited/canceled (517,519 ) $ 33.18 Outstanding at September 30, 2016 6,510,473 $ 33.60 Expected to vest at September 30, 2016 5,002,821 $ 34.01 The intrinsic value of RSUs vested was $58.4 million for the nine months ended September 30, 2016 . Aggregate intrinsic value of RSUs outstanding is $256.3 million as of September 30, 2016 . Unrecognized equity based compensation expense related to RSUs expected to vest over time is $148.1 million with a weighted average remaining vesting term of 1.7 years at September 30, 2016 .

Segment and Geographic Informat

Segment and Geographic Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic Information Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated on a regular basis by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its Chief Executive Officer. The CODM reviews financial information presented on a consolidated basis for purposes of making operating decisions, allocating resources and evaluating financial performance. As a result, the Company identified that it has one operating and reportable segment. The following table presents the activity related to the Company’s net revenue from Direct Retail sales derived through the Company’s sites and Other sales derived through sites operated by third parties and fees from third-party advertising distribution providers (in thousands): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Net revenue Direct Retail $ 832,398 $ 544,971 $ 2,299,901 $ 1,354,665 Other 29,127 49,001 95,900 155,430 Net revenue $ 861,525 $ 593,972 $ 2,395,801 $ 1,510,095 Revenue from external customers for each group of similar products and services are not reported to the CODM. Separate identification of this information for purposes of segment disclosure is impractical, as it is not readily available and the cost to develop it would be excessive. No individual country outside of the United States provided greater than 10% of total revenue. The following table presents revenue and long-lived assets by geographic area (in thousands): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Geographic net revenue: United States $ 787,801 $ 566,227 $ 2,226,395 $ 1,431,466 International (1) 73,724 27,745 169,406 78,629 Total $ 861,525 $ 593,972 $ 2,395,801 $ 1,510,095 (1) In the three and nine months ended September 30, 2015 , international net revenue included $0.7 million and $5.4 million , respectively, from our Australian business, which we sold in July 2015. September 30, December 31, Geographic long-lived assets: United States $ 205,113 $ 110,042 International 6,172 2,283 Total $ 211,285 $ 112,325

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax (benefit) expense was less than $(0.1 million) for the three months ended September 30, 2016 and 2015 , and $0.6 million and less than $0.1 million for the nine months ended September 30, 2016 and 2015 , respectively. The income tax expense recorded in the three and nine months ended September 30, 2016 and 2015 is primarily related to various foreign income tax assessments, state income taxes and to a lesser extent the amortization of goodwill for tax purposes for which there is no corresponding book deduction. Deferred income taxes reflect the impact of temporary differences between the amounts of assets and liabilities for financial reporting purposes and such amounts as measured by tax laws. The Company has deferred tax assets related to its net operating loss carryforwards accumulated since the fourth quarter of 2014 and related to net operating loss carryforwards of certain of its foreign subsidiaries. A valuation allowance against net deferred tax assets is required if, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company reassesses the valuation allowance on a quarterly basis and has provided a valuation allowance for the full amount of its net deferred tax assets. The Company had no unrecognized tax benefits as of September 30, 2016 and December 31, 2015 . The Company’s policy is to recognize interest and penalties related to unrecognized tax benefits as a component of income tax expense.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock The Company authorized 10,000,000 shares of undesignated preferred stock, $0.001 par value per share, for future issuance. As of September 30, 2016 , the Company had no shares of undesignated preferred stock issued or outstanding. Common Stock The Company authorized 500,000,000 shares of Class A common stock, $0.001 par value per share, and 164,000,000 shares of Class B common stock, $0.001 par value per share, of which 49,303,861 and 45,814,237 shares of Class A common stock and 36,100,764 and 38,496,562 shares of Class B common stock were outstanding as of September 30, 2016 and December 31, 2015 , respectively. The rights of the holders of Class A common stock and Class B common stock are identical, except with respect to voting and conversion rights. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to ten votes per share. The Class B common stock also has approval rights over certain corporate actions. Each share of Class B common stock may be converted into one share of Class A common stock at the option of its holder and will be automatically converted into one share of Class A common stock upon transfer thereof, subject to certain exceptions. In addition, upon the date on which the outstanding shares of Class B common stock represent less than 10% of the aggregate number of shares of the then outstanding Class A common stock and Class B common stock, or in the event of the affirmative vote or written consent of holders of at least 66 2/3% of the outstanding shares of Class B common stock, all outstanding shares of Class B common stock shall convert automatically into Class A common stock. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of common stock are entitled to receive dividends out of funds legally available if the Board, in its discretion, determines to issue dividends and then only at the times and in the amounts that the Board may determine. Since the IPO through September 30, 2016 , 34,563,880 shares of Class B common stock were converted to Class A common stock.

Credit Agreement

Credit Agreement	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Credit Agreement	Credit Agreement The Company has a credit agreement with Bank of America, which was renewed on July 31, 2016. The credit agreement provides the Company with a $20.0 million revolving line of credit to support direct borrowings and letters of credit, provided that a maximum of $5.0 million may be applied to direct borrowings under the revolving line of credit, plus an additional $45.0 million credit card program, for a maximum aggregate commitment of $65.0 million . The credit agreement is renewable on an annual basis and, if not renewed, will expire on July 31, 2017. The renewed credit agreement is on substantially the same terms and conditions as the prior credit agreement. Subject to the terms and conditions of the credit agreement, advances under the line of credit, if any, will bear interest at the LIBOR rate, plus 1.75% . Under the credit agreement, the Company is also required to maintain certain covenants, including debt service coverage, tangible net worth and unencumbered liquid assets, with which the Company was compliant at September 30, 2016 and December 31, 2015 . The Company did not borrow any amounts under the credit agreement during the three and nine months ended September 30, 2016 and the year ended December 31, 2015 .

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share Basic and diluted net loss per share is presented using the two class method required for participating securities. Class A and Class B common stock are the only outstanding equity in the Company since our IPO in October 2014. For additional information on the rights of the holders of Class A and Class B common stock, see Note 10, Stockholders' Equity , in the Notes to the Unaudited Consolidated and Condensed Financial Statements included in Part I, Item 1, Unaudited Consolidated and Condensed Financial Statements , of this Quarterly Report on Form 10-Q. Basic net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed using the weighted-average number of shares of common stock and, if dilutive, common stock equivalents outstanding during the period. The Company's common stock equivalents consist of shares issuable upon the release of restricted stock units, and to a lesser extent, the incremental shares of common stock issuable upon the exercise of stock options and unvested restricted stock. The dilutive effect of these common stock equivalents is reflected in diluted earnings per share by application of the treasury stock method. The Company's basic and diluted net loss per share are the same because the Company has generated net loss and common stock equivalents are excluded from diluted net loss per share because they have an antidilutive impact. The Company allocates undistributed earnings between the classes on a one-to-one basis when computing net loss per share. As a result, basic and diluted net loss per Class A and Class B shares are equivalent. The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Net loss $ (60,940 ) $ (15,478 ) $ (150,419 ) $ (61,948 ) Weighted average common shares used for basic and diluted net loss per share computation 85,105 83,886 84,779 83,569 Net loss per share: Basic and Diluted $ (0.72 ) $ (0.18 ) $ (1.77 ) $ (0.74 ) The following have been excluded from the computation of basic and diluted net loss per share as their effect would have been antidilutive: Three and nine months ended September 30, 2016 2015 Stock options 223,588 302,617 Restricted stock 60,000 6,001 Restricted stock units 6,510,473 4,915,338 Total 6,794,061 5,223,956

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Stock Compensation In March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-09, "Compensation - Stock Compensation" ("ASU 2016-09"). This ASU revises the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and an option to recognized gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. This ASU is effective for annual reporting periods beginning after December 15, 2016 and early adoption is permitted. Management is currently evaluating the impact of the adoption of this ASU on the Company's consolidated financial statements. Leases In February 2016, the FASB issued ASU No. 2016-02, "Leases" ("ASU 2016-02"). This ASU revises the accounting related to leases by requiring lessees to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplifies the accounting for sale and leaseback transactions. This ASU is effective for annual reporting periods beginning after December 15, 2018 and early adoption is permitted. Management is currently evaluating the impact of the adoption of this ASU on the Company’s consolidated financial statements. Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). This ASU is a comprehensive new revenue recognition model that requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. This ASU was originally effective for annual reporting periods beginning after December 15, 2016 and early adoption was not permitted. In August 2015, the FASB issued ASU No. 2015-14, "Revenue from Contracts with Customers – Deferral of the Effective Date" (ASU-2015-14), which defers the effective date of ASU 2014-09 for one year and permits early adoption as early as the original effective date of ASU 2014-09. Accordingly, ASU 2014-09 is now effective for annual reporting periods beginning after December 15, 2017 and early adoption is permitted only as of annual reporting periods beginning after December 31, 2016, including interim reporting periods within that reporting year. In March 2016, the FASB issued ASU No. 2016-08, "Revenue from Contracts with Customers - Principal versus Agent Considerations" ("ASU 2016-08"). This ASU clarifies the implementation guidance for principal versus agent considerations in ASU 2014-09. This ASU is effective at the same period as ASU 2015-14 and ASU 2014-09. Management is currently evaluating when to adopt the revenue recognition accounting pronouncements, which transition approach to use, and the impact of the adoption of this ASU on the Company’s consolidated financial statements.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Marketable Securities	Marketable Securities The Company classifies its marketable securities as "available-for-sale" securities. Available-for-sale securities are classified as short term investments and long-term investments on the consolidated balance sheets and are carried at fair value. Unrealized gains and losses on available-for-sale securities that are considered temporary are recorded, net of taxes, in the "Accumulated other comprehensive loss" caption of the Company’s consolidated balance sheets. Unrealized losses, excluding losses related to the credit rating of the security (credit losses), on available-for-sale securities that are considered other-than-temporary but relate to securities that the Company (i) does not intend to sell and (ii) will not be required to sell below cost are also recorded, net of taxes, in "Accumulated other comprehensive loss." Further, the Company does not believe it will be required to sell such securities below cost. Therefore, the only other-than-temporary losses the Company records in "Other income, net" in its consolidated statements of operations are related to credit losses. As of September 30, 2016 , the Company’s available-for-sale securities consisted of investment securities. The maturities of the Company’s long-term marketable securities generally range from one to three years.
Revenue Recognition	Revenue Recognition The Company generates net revenue through product sales generated primarily through the sites of the Company's five distinct brands and through sites operated by third parties. The Company recognizes revenue for product sales generated through the sites of the Company's five distinct brands and through sites operated by third parties only when the following four criteria are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company recognizes net revenue from sales of its products upon delivery to the customer. The Company records product revenue at the gross amount as the Company is the primary obligor with the customer and provides the primary customer service for all products sold, has latitude in establishing price and selecting products sold, has discretion in selecting suppliers of products sold, maintains inventory risk from shipment through delivery date and upon accepting returns, and has credit risk. Net revenue includes shipping costs charged to the customer and is recorded net of taxes collected from customers, which are remitted to governmental authorities. Cash discounts, returns and rebates are deducted from gross revenue in determining net revenue. In addition, the Company defers revenue when cash is collected from its customer prior to the satisfaction of the revenue recognition criteria. The Company maintains a membership rewards program that allows enrolled customers to earn points which can be redeemed for future purchases. The Company defers a portion of its revenue associated with rewards that are ultimately expected to be redeemed prior to expiration. The Company also earns revenue through third-party advertisers that pay based on the number of advertisement related clicks, actions, or impressions for advertisements placed on the Company's sites. Revenue earned under these arrangements is included in net revenue and is recognized in the period in which the click, action, or impression occurs.
Recent Accounting Pronouncements	Stock Compensation In March 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-09, "Compensation - Stock Compensation" ("ASU 2016-09"). This ASU revises the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and an option to recognized gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. This ASU is effective for annual reporting periods beginning after December 15, 2016 and early adoption is permitted. Management is currently evaluating the impact of the adoption of this ASU on the Company's consolidated financial statements. Leases In February 2016, the FASB issued ASU No. 2016-02, "Leases" ("ASU 2016-02"). This ASU revises the accounting related to leases by requiring lessees to recognize a lease liability and a right-of-use asset for all leases. The new lease guidance also simplifies the accounting for sale and leaseback transactions. This ASU is effective for annual reporting periods beginning after December 15, 2018 and early adoption is permitted. Management is currently evaluating the impact of the adoption of this ASU on the Company’s consolidated financial statements. Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). This ASU is a comprehensive new revenue recognition model that requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. This ASU was originally effective for annual reporting periods beginning after December 15, 2016 and early adoption was not permitted. In August 2015, the FASB issued ASU No. 2015-14, "Revenue from Contracts with Customers – Deferral of the Effective Date" (ASU-2015-14), which defers the effective date of ASU 2014-09 for one year and permits early adoption as early as the original effective date of ASU 2014-09. Accordingly, ASU 2014-09 is now effective for annual reporting periods beginning after December 15, 2017 and early adoption is permitted only as of annual reporting periods beginning after December 31, 2016, including interim reporting periods within that reporting year. In March 2016, the FASB issued ASU No. 2016-08, "Revenue from Contracts with Customers - Principal versus Agent Considerations" ("ASU 2016-08"). This ASU clarifies the implementation guidance for principal versus agent considerations in ASU 2014-09. This ASU is effective at the same period as ASU 2015-14 and ASU 2014-09. Management is currently evaluating when to adopt the revenue recognition accounting pronouncements, which transition approach to use, and the impact of the adoption of this ASU on the Company’s consolidated financial statements.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Property and Equipment	Depreciation and amortization on property and equipment is calculated on the straight-line method over the estimated useful lives of the assets as follows: Class Range of Life (In Years) Furniture and computer equipment 3 to 7 Site and software development costs 2 Leasehold improvements Lesser of useful life or lease term Building 30

Marketable Securities and Fai22

Marketable Securities and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of Marketable Securities	The following tables present details of the Company’s marketable securities as of September 30, 2016 and December 31, 2015 (in thousands): September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 54,327 $ 21 $ (10 ) $ 54,338 Commercial paper 5,135 — (2 ) 5,133 Long-term: Investment securities 41,564 163 (9 ) 41,718 Total $ 101,026 $ 184 $ (21 ) $ 101,189 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 16,908 $ — $ (13 ) $ 16,895 Long-term: Investment securities 80,172 2 (291 ) 79,883 Total $ 97,080 $ 2 $ (304 ) $ 96,778
Schedule of the Fair Value of the Company's Financial Assets Measured at Fair Value on a Recurring Basis Based on the Three-Tier Value Hierarchy	The following tables set forth the fair value of the Company’s financial assets measured at fair value on a recurring basis as of September 30, 2016 and December 31, 2015 based on the three-tier value hierarchy (in thousands): September 30, 2016 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 88,265 $ — $ — $ 88,265 Commercial paper — 5,133 — 5,133 Short-term investments: Certificates of deposit 25,000 — — 25,000 Investment securities — 54,338 — 54,338 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 41,718 — 41,718 Total $ 118,265 $ 101,189 $ — $ 219,454 December 31, 2015 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 267,300 $ — $ — $ 267,300 Short-term investments: Certificates of deposit 35,000 — — 35,000 Investment securities — 16,895 — 16,895 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 79,883 — 79,883 Total $ 307,300 $ 96,778 $ — $ 404,078

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The following table summarizes intangible assets as of September 30, 2016 and December 31, 2015 (in thousands): Weighted - Average Amortization Period (Years) September 30, 2016 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (1,203 ) $ 697 Technology 3 1,453 (40 ) $ 1,413 Customer relationships 5 1,300 (823 ) 477 Other intangibles 3 373 (354 ) 19 Total $ 5,026 $ (2,420 ) $ 2,606 Weighted - Average Amortization Period (Years) December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (918 ) $ 982 Customer relationships 5 1,300 (628 ) 672 Non-compete agreements 3 - 5 100 (81 ) 19 Other intangibles 3 373 (270 ) 103 Domain names 5 2,687 (2,685 ) 2 Total $ 6,360 $ (4,582 ) $ 1,778

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	The following table summarizes property and equipment, net as of September 30, 2016 and December 31, 2015 (in thousands): September 30, December 31, Furniture and computer equipment $ 127,565 $ 68,416 Site and software development costs 68,906 50,907 Leasehold improvements 58,322 29,315 Construction in progress 23,364 27,563 Building (leased - Note 6) 29,856 — 308,013 176,201 Less accumulated depreciation and amortization (96,728 ) (63,876 ) Property and equipment, net $ 211,285 $ 112,325

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Equity based compensation
Summary of Activity Relating to Stock Options	The following table presents activity relating to stock options for the nine months ended September 30, 2016 : Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Outstanding at December 31, 2015 279,591 $ 2.98 5.5 Options exercised (55,827 ) $ 2.98 Options forfeited/canceled (176 ) $ 3.42 Outstanding at September 30, 2016 223,588 $ 2.98 4.7 Exercisable at September 30, 2016 223,588 $ 2.98 4.7
Restricted common units
Equity based compensation
Summary of Activity Relating to Restricted Stock	The following table presents activity relating to restricted common stock for the nine months ended September 30, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 1,993 $ 4.75 Restricted stock granted 60,000 $ 44.34 Restricted stock vested (1,993 ) $ 4.75 Unvested at September 30, 2016 60,000 $ 39.37 Expected to vest at September 30, 2016 49,171 $ 39.37
Restricted stock units
Equity based compensation
Summary of Activity Relating to Restricted Stock	The following table presents activity relating to RSUs for the nine months ended September 30, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 5,607,867 $ 28.30 RSUs granted 2,851,452 $ 39.65 RSUs vested (1,431,327 ) $ 25.14 RSUs forfeited/canceled (517,519 ) $ 33.18 Outstanding at September 30, 2016 6,510,473 $ 33.60 Expected to vest at September 30, 2016 5,002,821 $ 34.01

Segment and Geographic Inform26

Segment and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Activity Related to Net Revenue	The following table presents the activity related to the Company’s net revenue from Direct Retail sales derived through the Company’s sites and Other sales derived through sites operated by third parties and fees from third-party advertising distribution providers (in thousands): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Net revenue Direct Retail $ 832,398 $ 544,971 $ 2,299,901 $ 1,354,665 Other 29,127 49,001 95,900 155,430 Net revenue $ 861,525 $ 593,972 $ 2,395,801 $ 1,510,095
Schedule of Net Revenue and Long-Lived Assets by Geographic Area	The following table presents revenue and long-lived assets by geographic area (in thousands): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Geographic net revenue: United States $ 787,801 $ 566,227 $ 2,226,395 $ 1,431,466 International (1) 73,724 27,745 169,406 78,629 Total $ 861,525 $ 593,972 $ 2,395,801 $ 1,510,095 (1) In the three and nine months ended September 30, 2015 , international net revenue included $0.7 million and $5.4 million , respectively, from our Australian business, which we sold in July 2015. September 30, December 31, Geographic long-lived assets: United States $ 205,113 $ 110,042 International 6,172 2,283 Total $ 211,285 $ 112,325

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 Per Share	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Net loss $ (60,940 ) $ (15,478 ) $ (150,419 ) $ (61,948 ) Weighted average common shares used for basic and diluted net loss per share computation 85,105 83,886 84,779 83,569 Net loss per share: Basic and Diluted $ (0.72 ) $ (0.18 ) $ (1.77 ) $ (0.74 )
Schedule of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders as their Effect Would Have Been Antidilutive	The following have been excluded from the computation of basic and diluted net loss per share as their effect would have been antidilutive: Three and nine months ended September 30, 2016 2015 Stock options 223,588 302,617 Restricted stock 60,000 6,001 Restricted stock units 6,510,473 4,915,338 Total 6,794,061 5,223,956

Basis of Presentation (Details)

Basis of Presentation (Details) supplier in Thousands, product in Millions	9 Months Ended
	Sep. 30, 2016brandproductsupplier
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Minimum number of products offered | product	7
Minimum number of suppliers providing products offered | supplier	7
Number of distinct brands | brand	5

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Details)	9 Months Ended
	Sep. 30, 2016brand
Property and equipment, net
Number of distinct brands	5
Furniture and computer equipment | Minimum
Property and equipment, net
Useful life (Years)	3 years
Furniture and computer equipment | Maximum
Property and equipment, net
Useful life (Years)	7 years
Site and software development costs
Property and equipment, net
Useful life (Years)	2 years
Building
Property and equipment, net
Useful life (Years)	30 years
Investment securities | Minimum
Property and equipment, net
Maturity period of marketable securities	1 year
Investment securities | Maximum
Property and equipment, net
Maturity period of marketable securities	3 years

Marketable Securities and Fai30

Marketable Securities and Fair Value Measurements (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Marketable securities and fair value measurements
Other than temporary impairment losses	$ 0	$ 0	$ 0	$ 0
Amortized Cost	101,026,000		101,026,000		$ 97,080,000
Gross Unrealized Gains	184,000		184,000		2,000
Gross Unrealized Losses	(21,000)		(21,000)		(304,000)
Estimated Fair Value	101,189,000		101,189,000		96,778,000
Investment securities
Marketable securities and fair value measurements
Amortized Cost	54,327,000		54,327,000		16,908,000
Gross Unrealized Gains	21,000		21,000		0
Gross Unrealized Losses	(10,000)		(10,000)		(13,000)
Estimated Fair Value	54,338,000		54,338,000		16,895,000
Commercial paper
Marketable securities and fair value measurements
Amortized Cost	5,135,000		5,135,000
Gross Unrealized Gains	0		0
Gross Unrealized Losses	(2,000)		(2,000)
Estimated Fair Value	5,133,000		5,133,000
Investment securities
Marketable securities and fair value measurements
Amortized Cost	41,564,000		41,564,000		80,172,000
Gross Unrealized Gains	163,000		163,000		2,000
Gross Unrealized Losses	(9,000)		(9,000)		(291,000)
Estimated Fair Value	$ 41,718,000		$ 41,718,000		$ 79,883,000
Minimum | Investment securities
Marketable securities and fair value measurements
Maturity period of marketable securities			1 year
Maximum | Investment securities
Marketable securities and fair value measurements
Maturity period of marketable securities			3 years

Marketable Securities and Fai31

Marketable Securities and Fair Value Measurements (Details 2) - Recurring - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Marketable securities and fair value measurements
Total	$ 219,454	$ 404,078
Cash equivalents
Marketable securities and fair value measurements
Money market funds	88,265	267,300
Commercial paper	5,133
Investment securities
Marketable securities and fair value measurements
Certificates of deposit	25,000	35,000
Investment securities	54,338	16,895
Restricted cash
Marketable securities and fair value measurements
Certificates of deposit	5,000	5,000
Investment securities
Marketable securities and fair value measurements
Investment securities	41,718	79,883
Level 1
Marketable securities and fair value measurements
Total	118,265	307,300
Level 1 | Cash equivalents
Marketable securities and fair value measurements
Money market funds	88,265	267,300
Level 1 | Investment securities
Marketable securities and fair value measurements
Certificates of deposit	25,000	35,000
Level 1 | Restricted cash
Marketable securities and fair value measurements
Certificates of deposit	5,000	5,000
Level 2
Marketable securities and fair value measurements
Total	101,189	96,778
Level 2 | Cash equivalents
Marketable securities and fair value measurements
Commercial paper	5,133
Level 2 | Investment securities
Marketable securities and fair value measurements
Investment securities	54,338	16,895
Level 2 | Investment securities
Marketable securities and fair value measurements
Investment securities	$ 41,718	$ 79,883

Intangible Assets and Goodwil32

Intangible Assets and Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Intangible assets
Gross Carrying Amount	$ 5,026		$ 5,026		$ 6,360
Accumulated Amortization	(2,420)		(2,420)		(4,582)
Net Book Value	2,606		2,606		1,778
Amortization expense related to intangibles	200	$ 200	600	$ 700
Goodwill	1,900		$ 1,900		$ 1,900
Trademarks
Intangible assets
Weighted - Average Amortization Period (Years)			5 years		5 years
Gross Carrying Amount	1,900		$ 1,900		$ 1,900
Accumulated Amortization	(1,203)		(1,203)		(918)
Net Book Value	697		$ 697		$ 982
Technology
Intangible assets
Weighted - Average Amortization Period (Years)			3 years
Gross Carrying Amount	1,453		$ 1,453
Accumulated Amortization	(40)		(40)
Net Book Value	1,413		$ 1,413
Customer relationships
Intangible assets
Weighted - Average Amortization Period (Years)			5 years		5 years
Gross Carrying Amount	1,300		$ 1,300		$ 1,300
Accumulated Amortization	(823)		(823)		(628)
Net Book Value	477		$ 477		672
Non-compete agreements
Intangible assets
Gross Carrying Amount					100
Accumulated Amortization					(81)
Net Book Value					$ 19
Non-compete agreements | Minimum
Intangible assets
Weighted - Average Amortization Period (Years)					3 years
Non-compete agreements | Maximum
Intangible assets
Weighted - Average Amortization Period (Years)					5 years
Other intangibles
Intangible assets
Weighted - Average Amortization Period (Years)			3 years		3 years
Gross Carrying Amount	373		$ 373		$ 373
Accumulated Amortization	(354)		(354)		(270)
Net Book Value	$ 19		$ 19		$ 103
Domain names
Intangible assets
Weighted - Average Amortization Period (Years)					5 years
Gross Carrying Amount					$ 2,687
Accumulated Amortization					(2,685)
Net Book Value					$ 2

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Property and equipment, net
Property and equipment, gross	$ 308,013		$ 308,013		$ 176,201
Less accumulated depreciation and amortization	(96,728)		(96,728)		(63,876)
Property and equipment, net	211,285		211,285		112,325
Depreciation and amortization	15,200	$ 9,000	37,900	$ 22,700
Furniture and computer equipment
Property and equipment, net
Property and equipment, gross	127,565		127,565		68,416
Site and software development costs
Property and equipment, net
Property and equipment, gross	68,906		68,906		50,907
Leasehold improvements
Property and equipment, net
Property and equipment, gross	58,322		58,322		29,315
Construction in progress
Property and equipment, net
Property and equipment, gross	23,364		23,364		27,563
Building
Property and equipment, net
Property and equipment, gross	$ 29,856		$ 29,856		$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Dec. 31, 2015
Property and Equipment, Net
Rental expense under operating leases	$ 9,100	$ 3,800	$ 23,900	$ 12,300
Letter of credit issued as security for lease agreements	10,600		10,600			$ 5,900
Future minimum lease payments for non-cancelable lease	358,500		358,500
Lease financing obligation	28,900		28,900			$ 0
Land lease expense	100		100
Interest expense	800		800
Future minimum commitments related to financing obligation, principal	2,100		2,100
Future minimum commitments related to financing obligation, interest	$ 12,000		$ 12,000
Lease Financing Obligation
Property and Equipment, Net
Letter of credit issued as security for lease agreements					$ 1,200

Commitments and Contingencies35

Commitments and Contingencies (Details 2) $ in Millions	Sep. 30, 2016USD ($)
Sales and other similar tax assessments
Contingencies
Aggregate amount of claims	$ 28.2

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
2014 Plan
Equity based compensation
Number of shares authorized	8,603,066
Restricted stock units | 2014 Plan
Equity based compensation
Shares issued under plan	5,949,611
Stock options
Common stock options
Outstanding at the beginning of the period (in shares)	279,591
Options exercised (in shares)	(55,827)
Options forfeited/canceled (in shares)	(176)
Outstanding at the end of the period (in shares)	223,588	279,591
Exercisable at the end of the period (in shares)	223,588
Weighted- Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 2.98
Exercised (in dollars per share)	2.98
Options forfeited/canceled (in dollars per share)	3.42
Outstanding at the end of the period (in dollars per share)	2.98	$ 2.98
Exercisable at the end of the period (in dollars per share)	$ 2.98
Weighted- Average Remaining Contractual Term (Years)
Outstanding at the beginning of the period	4 years 264 days	5 years 6 months
Outstanding at the end of the period	4 years 264 days	5 years 6 months
Exercisable at the end of the period	4 years 264 days
Additional disclosures
Aggregate intrinsic value of stock options exercised	$ 2.1
Aggregate intrinsic value of stock options outstanding and repurchased	$ 8.1

Equity-Based Compensation (De37

Equity-Based Compensation (Details 2) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Restricted stock
Restricted stock and units
Outstanding at the beginning of the period (in shares) | shares	1,993
Restricted stock granted (in shares) | shares	60,000
Vested (in shares) | shares	(1,993)
Unvested at the end of the period (in shares) | shares	60,000
Expected to vest at the end of the period (in shares) | shares	49,171
Weighted-Average Grant-Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 4.75
Granted (in dollars per share) | $ / shares	44.34
Vested (in dollars per share) | $ / shares	4.75
Unvested at the end of the period (in dollars per share) | $ / shares	39.37
Expected to vest at the end of the period (in dollars per share) | $ / shares	$ 39.37
Additional information
Intrinsic value of stock vested and repurchased (less than) | $	$ 0.1
Intrinsic value of stock unvested | $	2.4
Unrecognized share-based compensation | $	$ 1.8
Weighted average remaining vesting term for options expected to vest	2 years 2 months 12 days
Restricted stock units
Restricted stock and units
Outstanding at the beginning of the period (in shares) | shares	5,607,867
Restricted stock granted (in shares) | shares	2,851,452
Vested (in shares) | shares	(1,431,327)
Forfeited/canceled (in shares) | shares	(517,519)
Unvested at the end of the period (in shares) | shares	6,510,473
Expected to vest at the end of the period (in shares) | shares	5,002,821
Weighted-Average Grant-Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 28.30
Granted (in dollars per share) | $ / shares	39.65
Vested (in dollars per share) | $ / shares	25.14
Forfeited/canceled (in dollars per share) | $ / shares	33.18
Unvested at the end of the period (in dollars per share) | $ / shares	33.60
Expected to vest at the end of the period (in dollars per share) | $ / shares	$ 34.01
Additional information
Intrinsic value of stock vested | $	$ 58.4
Aggregate intrinsic value | $	256.3
Unrecognized share-based compensation | $	$ 148.1
Weighted average remaining vesting term for options expected to vest	1 year 245 days

Segment and Geographic Inform38

Segment and Geographic Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)segment	Sep. 30, 2015USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			1
Number of reportable segments | segment			1
Net revenue
Direct Retail	$ 832,398	$ 544,971	$ 2,299,901	$ 1,354,665
Other	29,127	49,001	95,900	155,430
Net revenue	$ 861,525	$ 593,972	$ 2,395,801	$ 1,510,095

Segment and Geographic Inform39

Segment and Geographic Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Geographic revenue and long-lived assets
Geographic net revenue	$ 861,525	$ 593,972	$ 2,395,801	$ 1,510,095
Geographic long-lived assets	211,285		211,285		$ 112,325
United States
Geographic revenue and long-lived assets
Geographic net revenue	787,801	566,227	2,226,395	1,431,466
Geographic long-lived assets	205,113		205,113		110,042
International
Geographic revenue and long-lived assets
Geographic net revenue	73,724	27,745	169,406	78,629
Geographic long-lived assets	$ 6,172		$ 6,172		$ 2,283
AUSTRALIA
Geographic revenue and long-lived assets
Geographic net revenue		$ 700		$ 5,400

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax (benefit) expense	$ (83,000)	$ (88,000)	$ 555,000	$ 31,000
Unrecognized tax benefits	$ 0		$ 0		$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details)	9 Months Ended	24 Months Ended
	Sep. 30, 2016vote$ / sharesshares	Sep. 30, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares
Stockholders' Equity
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A common stock
Common stock
Common stock, shares authorized (in shares)	500,000,000	500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001
Common stock, shares outstanding (in shares)	49,303,861	49,303,861	45,814,237
Number of votes each holder is entitled | vote	1
Class B common stock
Common stock
Common stock, shares authorized (in shares)	164,000,000	164,000,000	164,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001
Common stock, shares outstanding (in shares)	36,100,764	36,100,764	38,496,562
Number of votes each holder is entitled | vote	10
Conversion ratio following the completion of the offering	1
Conversion ratio upon transfer	1
Number of shares converted into Class A shares		34,563,880
Class B common stock | Minimum
Common stock
Percentage of outstanding shares of Class B common stock that shall convert automatically in the event of the affirmative vote or written consent of holders	66.67%
Class B common stock | Maximum
Common stock
Aggregate number of shares outstanding Class A common stock and Class B common stock that shall convert automatically (less than)	10.00%

Credit Agreement (Details)

Credit Agreement (Details) - USD ($)	Jul. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Amount borrowed under the agreement		$ 0	$ 0
Line of credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 65,000,000
Line of credit | LIBOR
Line of Credit Facility [Line Items]
Basis spread	1.75%
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 20,000,000
Line of credit | Credit card program
Line of Credit Facility [Line Items]
Maximum borrowing capacity	45,000,000
Direct Borrowings | Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 5,000,000

Net Loss per Share (Details)

Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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	$ (60,940)	$ (15,478)	$ (150,419)	$ (61,948)
Weighted average common shares used for basic and diluted net loss per share computation (in shares)	85,105	83,886	84,779	83,569
Net loss per share:
Basic and Diluted (in dollars per share)	$ (0.72)	$ (0.18)	$ (1.77)	$ (0.74)

Net Loss per Share (Details 2)

Net Loss per Share (Details 2) - 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]
Number of antidilutive shares excluded from computation of basic and diluted net loss per share	6,794,061	5,223,956	6,794,061	5,223,956
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of antidilutive shares excluded from computation of basic and diluted net loss per share	223,588	302,617	223,588	302,617
Restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of antidilutive shares excluded from computation of basic and diluted net loss per share	60,000	6,001	60,000	6,001
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of antidilutive shares excluded from computation of basic and diluted net loss per share	6,510,473	4,915,338	6,510,473	4,915,338