Wayfair (W) 10-Q 9 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 30, 2016
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	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A common stock
Entity Common Stock, Shares Outstanding		47,291,156
Class B common stock
Entity Common Stock, Shares Outstanding		37,423,591

CONSOLIDATED AND CONDENSED BALA

CONSOLIDATED AND CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 248,798	$ 334,176
Short-term investments	60,656	51,895
Accounts receivable, net of allowance of $3,091 and $2,767 at March 31, 2016 and December 31, 2015, respectively	11,854	9,906
Inventories	17,763	19,900
Prepaid expenses and other current assets	85,170	76,446
Total current assets	424,241	492,323
Property and equipment, net	162,594	112,325
Goodwill and intangible assets, net	3,505	3,702
Long-term investments	70,315	79,883
Other noncurrent assets	6,772	6,348
Total assets	667,427	694,581
Current liabilities
Accounts payable	251,023	270,913
Accrued expenses	60,600	51,560
Deferred revenue	48,691	50,884
Other current liabilities	27,813	23,669
Total current liabilities	388,127	397,026
Other liabilities	74,294	55,010
Total liabilities	$ 462,421	$ 452,036
Commitments and contingencies
Convertible preferred stock, $0.001 par value per share: 10,000,000 shares authorized and none issued at March 31, 2016 and December 31, 2015	$ 0	$ 0
Stockholders’ equity:
Additional paid-in capital	381,663	378,162
Accumulated deficit	(176,770)	(135,565)
Accumulated other comprehensive loss	28	(136)
Total stockholders’ equity	205,006	242,545
Total liabilities and stockholders’ equity	667,427	694,581
Class A common stock
Stockholders’ equity:
Common stock	47	46
Class B common stock
Stockholders’ equity:
Common stock	$ 38	$ 38

CONSOLIDATED AND CONDENSED BAL3

CONSOLIDATED AND CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts receivable allowance for doubtful accounts	$ 3,091	$ 2,767
Convertible redeemable preferred units, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible redeemable preferred units, shares authorized	10,000,000	10,000,000
Convertible redeemable preferred units, shares issued	0	0
Class A common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	46,966,564	45,814,237
Common stock, shares outstanding	46,966,564	45,814,237
Class B common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	164,000,000	164,000,000
Common stock, shares issued	37,664,049	38,496,562
Common stock, shares outstanding	37,664,049	38,496,562

CONSOLIDATED AND CONDENSED STAT

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net revenue	$ 747,348	$ 424,371
Cost of goods sold	568,292	321,536
Gross profit	179,056	102,835
Operating expenses:
Customer service and merchant fees	27,350	15,978
Advertising	97,677	57,999
Merchandising, marketing and sales	37,856	23,234
Operations, technology, general and administrative	58,282	32,870
Total operating expenses	221,165	130,081
Loss from operations	(42,109)	(27,246)
Interest income, net	552	264
Other income (expense), net	669	(108)
Loss before income taxes	(40,888)	(27,090)
Provision for income taxes	317	46
Net loss	$ (41,205)	$ (27,136)
Net loss per share, basic and diluted (in dollars per share)	$ (0.49)	$ (0.33)
Weighted average number of common stock outstanding used in computing per share amounts, basic and diluted	84,445	83,210

CONSOLIDATED AND CONDENSED STA5

CONSOLIDATED AND CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (41,205)	$ (27,136)
Other comprehensive loss:
Foreign currency translation adjustments	(333)	144
Net unrealized gain on available-for-sale investments	497	46
Comprehensive loss	$ (41,041)	$ (26,946)

CONSOLIDATED AND CONDENSED STA6

CONSOLIDATED AND CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities
Net loss	$ (41,205)	$ (27,136)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	10,487	6,744
Equity based compensation	9,715	7,642
Other non-cash adjustments	(156)	231
Changes in operating assets and liabilities:
Accounts receivable	(1,941)	(2,128)
Inventories	2,142	(240)
Prepaid expenses and other current assets	(8,643)	(15,327)
Accounts payable and accrued expenses	(29,097)	(16,800)
Deferred revenue and other liabilities	7,926	12,151
Other assets	(432)	(339)
Net cash used in operating activities	(51,204)	(35,202)
Cash flows from investing activities
Purchase of short-term and long-term investments	(28,489)	(104,233)
Sale and maturities of short-term investments	29,620	10,000
Purchase of property and equipment	(23,927)	(12,051)
Site and software development costs	(5,451)	(4,115)
Other investing activities, net	0	302
Net cash used in investing activities	(28,247)	(110,097)
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(6,621)	(4,251)
Net proceeds from exercise of stock options	51	15
Net cash used in financing activities	(6,570)	(4,236)
Effect of exchange rate changes on cash and cash equivalents	643	(242)
Net decrease in cash and cash equivalents	(85,378)	(149,777)
Cash and cash equivalents
Beginning of period	334,176	355,859
End of period	248,798	206,082
Supplemental disclosure of non-cash investing activities
Purchase of property and equipment included in accounts payable and accrued expenses and in other liabilities	19,186	5,988
Construction costs capitalized under finance lease obligations	$ 13,077	$ 9,900

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 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.com, 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 March 31, 2016 , the consolidated statements of operations, consolidated statements of comprehensive loss, and consolidated statements of cash flows for the periods ended March 31, 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 March 31, 2016 and statements of operations, comprehensive loss, and cash flows for the periods ended March 31, 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 March 31, 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	3 Months Ended
	Mar. 31, 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 three months ended March 31, 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 .

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	Marketable Securities and Fair Value Measurements Marketable Securities As of March 31, 2016 and December 31, 2015 , all of the Company’s marketable securities were classified as available-for-sale and their estimated fair values were $96.0 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. During the three months ended March 31, 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 following tables present details of the Company’s marketable securities as of March 31, 2016 and December 31, 2015 (in thousands): March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 25,646 $ 15 $ (5 ) $ 25,656 Long-term: Investment securities 70,130 220 (35 ) 70,315 Total $ 95,776 $ 235 $ (40 ) $ 95,971 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 March 31, 2016 and December 31, 2015 based on the three-tier value hierarchy (in thousands): March 31, 2016 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 165,476 $ — $ — $ 165,476 Short-term investments: Certificates of deposit 35,000 — — 35,000 Investment securities — 25,656 — 25,656 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 70,315 — 70,315 Total $ 205,476 $ 95,971 $ — $ 301,447 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	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill The following table summarizes intangible assets as of March 31, 2016 and December 31, 2015 (in thousands): Weighted - Average Amortization Period (Years) March 31, 2016 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (1,014 ) $ 886 Customer relationships 5 1,300 (693 ) 607 Non-compete agreements 3 - 5 100 (89 ) 11 Other intangibles 3 373 (298 ) 75 Domain names 5 2,687 (2,685 ) 2 Total $ 6,360 $ (4,779 ) $ 1,581 Weighted-Average December 31, 2015 Amortization Period (Years) 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 and $0.3 million for the three months ended March 31, 2016 and 2015 , respectively. Goodwill as of March 31, 2016 was $1.9 million , unchanged from December 31, 2015 .

Property and Equipment, net

Property and Equipment, net	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The following table summarizes property and equipment, net as of March 31, 2016 and December 31, 2015 (in thousands): March 31, December 31, Furniture and computer equipment $ 78,617 $ 68,416 Site and software development costs 55,311 50,907 Leasehold improvements 30,751 29,315 Construction in progress 70,646 27,563 235,325 176,201 Less accumulated depreciation and amortization (72,731 ) (63,876 ) Property and equipment, net $ 162,594 $ 112,325 Property and equipment depreciation and amortization expense was $10.3 million and $6.5 million for the three months ended March 31, 2016 and 2015 , respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 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 $7.1 million and $4.1 million in the three months ended March 31, 2016 and 2015 , respectively. The Company has issued letters of credit for approximately $7.0 million and $5.9 million as security for these lease agreements as of March 31, 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 $ 216.7 million in the aggregate. 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, and Texas, and subsequent to March 31, 2016, New Jersey. 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 $12.9 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 On September 2, 2015, a putative class action complaint was filed against the Company in the U.S. District Court for the Southern District of New York (Dingee v. Wayfair Inc., et al., Case No. 1:15-cv-06941) by an individual on behalf of himself and on behalf of all other similarly situated individuals, (or collectively, the "Dingee Plaintiffs"), under sections 10(b) and 20(a) of the Exchange Act related to a drop in stock price that had followed a report issued by Citron Research. On September 3, 2015 a second putative class action complaint was filed, asserting nearly identical claims (Jenkins v. Wayfair Inc., et al., Case No. 1:15-cv-06985). On November 2, 2015, the plaintiff in the Dingee action moved to consolidate the two lawsuits, and to designate himself as lead plaintiff in the class action and his attorney as lead counsel for the class. On November 3, 2015 plaintiff in the Jenkins action voluntarily dismissed his complaint. As a result, only the Dingee action remains pending. On November 13, 2015, the Court appointed Dingee as lead plaintiff. On January 11, 2016, Dingee filed an amended complaint along with a second named plaintiff, Michael Lamp. The Dingee Plaintiff’s complaint seeks class certification, damages in an unspecified amount, and attorney’s fees and costs. We have moved to dismiss the case; briefing on the motion to dismiss was completed on April 1, 2016 and the parties are awaiting a decision. The Company believes a loss is not probable and intends to defend the lawsuit vigorously. On February 2, 2016, a putative class action complaint was filed against the Company in the U.S. District Court for the Central District of California (Carson, et al., v. Wayfair Inc., Case No. 2:16-cv-00716) by two individuals on behalf of themselves and on behalf of all other similarly situated individuals (collectively, the "Carson Plaintiffs"). The complaint alleges that Wayfair engaged in a deceptive marketing campaign in which the Company advertised certain “original” or “regular” retail prices, which the Carson Plaintiffs allege were false. The Carson Plaintiffs’ complaint seeks injunctive relief, attorney’s fees, punitive damages and damages. The Company believes a loss is not probable and intends to defend the lawsuit vigorously. The Company is subject to legal proceedings and claims in the ordinary course of business. However, the Company is not currently aware of any legal proceedings or claims that it believes will have, individually or in the aggregate, a material adverse effect on the Company’s financial position, results of operations or cash flows.

Equity-Based Compensation

Equity-Based Compensation	3 Months Ended
	Mar. 31, 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, 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 4,192,719 shares had been issued as of March 31, 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 three months ended March 31, 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 (16,772 ) $ 3.10 Outstanding at March 31, 2016 262,819 $ 2.97 5.2 Exercisable at March 31, 2016 262,603 $ 2.97 5.2 Expected to vest as of March 31, 2016 133 $ 3.42 5.2 Intrinsic value of stock options exercised was $0.7 million for the three months ended March 31, 2016 . Aggregate intrinsic value of stock options outstanding and currently exercisable is $10.6 million . Unrecognized equity based compensation expense related to stock options expected to vest is less than $0.1 million with a weighted average remaining vesting term of 0.3 years as of March 31, 2016 . The following table presents activity relating to restricted common stock for the three months ended March 31, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 1,993 $ 4.75 Restricted stock vested (1,993 ) $ 4.75 Unvested at March 31, 2016 — $ — Expected to vest as of March 31, 2016 — $ — The intrinsic value of restricted common stock vested was less than $0.1 million for the three months ended March 31, 2016 . All restricted common stock shares were fully vested at March 31, 2016 . The following table presents activity relating to RSUs for the three months ended March 31, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 5,607,867 $ 28.30 RSUs granted 1,094,560 $ 40.50 RSUs vested (462,881 ) $ 22.54 RSUs forfeited/canceled (68,726 ) $ 31.69 Outstanding at March 31, 2016 6,170,820 $ 30.86 Expected to vest as of March 31, 2016 4,562,931 $ 31.35 The intrinsic value of RSUs vested was $19.5 million for the three months ended March 31, 2016 . Aggregate intrinsic value of RSUs outstanding is $266.7 million as of March 31, 2016 . Unrecognized equity based compensation expense related to RSUs expected to vest is $115.3 million with a weighted average remaining vesting term of 1.7 years as of March 31, 2016 .

Segment and Geographic Informat

Segment and Geographic Information	3 Months Ended
	Mar. 31, 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 March 31, 2016 2015 Net revenue Direct Retail $ 711,846 $ 369,396 Other 35,502 54,975 Net revenue $ 747,348 $ 424,371 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 March 31, 2016 2015 Geographic net revenue: United States $ 705,921 $ 400,580 International (1) 41,427 23,791 Total $ 747,348 $ 424,371 (1) In the three months ended March 31, 2015 , international net revenue included $2.5 million from our Australian business, which we sold in July 2015. March 31, December 31, Geographic long-lived assets: United States $ 159,038 $ 110,042 International 3,556 2,283 Total $ 162,594 $ 112,325

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three months ended March 31, 2016 and 2015 , income tax expense of $0.3 million and less than $0.1 million was recorded, respectively. The income tax expense recorded in the three months ended March 31, 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 March 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 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 46,966,564 and 45,814,237 shares of Class A common stock and 37,664,049 and 38,496,562 shares of Class B common stock were outstanding as of March 31, 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 March 31, 2016 , 32,974,871 shares of Class B common stock were converted to Class A common stock.

Credit Agreement

Credit Agreement	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Credit Agreement	Credit Agreement The Company has a credit agreement with Bank of America, which provides the Company with an unused line of credit and a credit card program with a maximum commitment of $35.0 million , $45.0 million and $35.0 million for the periods of July 31, 2015 through September 30, 2015, October 1, 2015 through February 28, 2016 and March 1, 2016 through July 31, 2016, respectively, with the committed amounts of $10.0 million to be used for a revolving line of credit and to support letters of credit and the remainder to be used to support the Company’s credit card program. The credit agreement is renewable on an annual basis and, if not renewed, will expire on July 31, 2016. The Company is required to maintain certain covenants, including tangible net worth and unencumbered liquid assets, with which the Company was compliant at March 31, 2016 and December 31, 2015 . The Company did not borrow any amounts under the credit agreement during the three months ended March 31, 2016 and the year ended December 31, 2015 .

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 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. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 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 any time at the option of the stockholder, and will be automatically converted into one share of Class A common stock upon a sale or transfer, subject to certain limited 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 at least 66 2/3% of the outstanding shares of Class B common stock, all outstanding shares of Class B common stock will automatically convert into Class A common stock. Basic net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period. Diluted net income 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 March 31, 2016 2015 Net loss $ (41,205 ) $ (27,136 ) Weighted average common shares used for basic and diluted net loss per share computation 84,445 83,210 Net loss per share: Basic and Diluted $ (0.49 ) $ (0.33 ) The following have been excluded from the computation of basic and diluted net loss per share as their effect would have been antidilutive: Three months ended March 31, 2016 2015 Stock options 262,819 423,778 Restricted stock — 21,635 Restricted stock units 6,170,820 4,159,768 Total 6,433,639 4,605,181

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [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)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
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.

Marketable Securities and Fai21

Marketable Securities and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Marketable Securities	The following tables present details of the Company’s marketable securities as of March 31, 2016 and December 31, 2015 (in thousands): March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term: Investment securities $ 25,646 $ 15 $ (5 ) $ 25,656 Long-term: Investment securities 70,130 220 (35 ) 70,315 Total $ 95,776 $ 235 $ (40 ) $ 95,971 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 March 31, 2016 and December 31, 2015 based on the three-tier value hierarchy (in thousands): March 31, 2016 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 165,476 $ — $ — $ 165,476 Short-term investments: Certificates of deposit 35,000 — — 35,000 Investment securities — 25,656 — 25,656 Restricted cash: Certificate of deposit 5,000 — — 5,000 Long-term: Investment securities — 70,315 — 70,315 Total $ 205,476 $ 95,971 $ — $ 301,447 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)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The following table summarizes intangible assets as of March 31, 2016 and December 31, 2015 (in thousands): Weighted - Average Amortization Period (Years) March 31, 2016 Gross Carrying Amount Accumulated Amortization Net Book Value Trademarks 5 $ 1,900 $ (1,014 ) $ 886 Customer relationships 5 1,300 (693 ) 607 Non-compete agreements 3 - 5 100 (89 ) 11 Other intangibles 3 373 (298 ) 75 Domain names 5 2,687 (2,685 ) 2 Total $ 6,360 $ (4,779 ) $ 1,581 Weighted-Average December 31, 2015 Amortization Period (Years) 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)	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	The following table summarizes property and equipment, net as of March 31, 2016 and December 31, 2015 (in thousands): March 31, December 31, Furniture and computer equipment $ 78,617 $ 68,416 Site and software development costs 55,311 50,907 Leasehold improvements 30,751 29,315 Construction in progress 70,646 27,563 235,325 176,201 Less accumulated depreciation and amortization (72,731 ) (63,876 ) Property and equipment, net $ 162,594 $ 112,325

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Equity based compensation
Summary of Status and Activity for Awards of Stock Options	The following table presents activity relating to stock options for the three months ended March 31, 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 (16,772 ) $ 3.10 Outstanding at March 31, 2016 262,819 $ 2.97 5.2 Exercisable at March 31, 2016 262,603 $ 2.97 5.2 Expected to vest as of March 31, 2016 133 $ 3.42 5.2
Restricted common units
Equity based compensation
Summary of Status and Activity for Awards of Restricted Stock Units	The following table presents activity relating to restricted common stock for the three months ended March 31, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 1,993 $ 4.75 Restricted stock vested (1,993 ) $ 4.75 Unvested at March 31, 2016 — $ — Expected to vest as of March 31, 2016 — $ —
Restricted stock units
Equity based compensation
Summary of Status and Activity for Awards of Restricted Stock Units	The following table presents activity relating to RSUs for the three months ended March 31, 2016 : Shares Weighted- Average Grant Date Fair Value Outstanding at December 31, 2015 5,607,867 $ 28.30 RSUs granted 1,094,560 $ 40.50 RSUs vested (462,881 ) $ 22.54 RSUs forfeited/canceled (68,726 ) $ 31.69 Outstanding at March 31, 2016 6,170,820 $ 30.86 Expected to vest as of March 31, 2016 4,562,931 $ 31.35

Segment and Geographic Inform25

Segment and Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Schedule of Operating Information by 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 March 31, 2016 2015 Net revenue Direct Retail $ 711,846 $ 369,396 Other 35,502 54,975 Net revenue $ 747,348 $ 424,371
Schedule of 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 March 31, 2016 2015 Geographic net revenue: United States $ 705,921 $ 400,580 International (1) 41,427 23,791 Total $ 747,348 $ 424,371 (1) In the three months ended March 31, 2015 , international net revenue included $2.5 million from our Australian business, which we sold in July 2015. March 31, December 31, Geographic long-lived assets: United States $ 159,038 $ 110,042 International 3,556 2,283 Total $ 162,594 $ 112,325

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2016 2015 Net loss $ (41,205 ) $ (27,136 ) Weighted average common shares used for basic and diluted net loss per share computation 84,445 83,210 Net loss per share: Basic and Diluted $ (0.49 ) $ (0.33 )
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 months ended March 31, 2016 2015 Stock options 262,819 423,778 Restricted stock — 21,635 Restricted stock units 6,170,820 4,159,768 Total 6,433,639 4,605,181

Basis of Presentation (Details)

Basis of Presentation (Details) supplier in Thousands, product in Millions	3 Months Ended
	Mar. 31, 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

Marketable Securities and Fai28

Marketable Securities and Fair Value Measurements (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Marketable securities and fair value measurements
Other than temporary impairment losses	$ 0	$ 0
Amortized Cost	95,776,000		$ 97,080,000
Gross Unrealized Gains	235,000		2,000
Gross Unrealized Losses	(40,000)		(304,000)
Estimated Fair Value	95,971,000		96,778,000
Short-term
Marketable securities and fair value measurements
Amortized Cost	25,646,000		16,908,000
Gross Unrealized Gains	15,000		0
Gross Unrealized Losses	(5,000)		(13,000)
Estimated Fair Value	25,656,000		16,895,000
Long-term
Marketable securities and fair value measurements
Amortized Cost	70,130,000		80,172,000
Gross Unrealized Gains	220,000		2,000
Gross Unrealized Losses	(35,000)		(291,000)
Estimated Fair Value	$ 70,315,000		$ 79,883,000
Minimum | Long-term
Marketable securities and fair value measurements
Maturity period of marketable securities	1 year
Maximum | Long-term
Marketable securities and fair value measurements
Maturity period of marketable securities	3 years

Marketable Securities and Fai29

Marketable Securities and Fair Value Measurements (Details 2) - Recurring - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Marketable securities and fair value measurements
Total	$ 301,447	$ 404,078
Level 1
Marketable securities and fair value measurements
Total	205,476	307,300
Level 2
Marketable securities and fair value measurements
Total	95,971	96,778
Cash equivalents
Marketable securities and fair value measurements
Money market funds	165,476	267,300
Cash equivalents | Level 1
Marketable securities and fair value measurements
Money market funds	165,476	267,300
Short-term
Marketable securities and fair value measurements
Certificates of deposit	35,000	35,000
Investment securities	25,656	16,895
Short-term | Level 1
Marketable securities and fair value measurements
Certificates of deposit	35,000	35,000
Short-term | Level 2
Marketable securities and fair value measurements
Investment securities	25,656	16,895
Restricted cash
Marketable securities and fair value measurements
Certificates of deposit	5,000	5,000
Restricted cash | Level 1
Marketable securities and fair value measurements
Certificates of deposit	5,000	5,000
Long-term
Marketable securities and fair value measurements
Investment securities	70,315	79,883
Long-term | Level 2
Marketable securities and fair value measurements
Investment securities	$ 70,315	$ 79,883

Intangible Assets and Goodwil30

Intangible Assets and Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Intangible assets
Gross Carrying Amount	$ 6,360		$ 6,360
Accumulated Amortization	(4,779)		(4,582)
Net Book Value	1,581		1,778
Amortization expense related to intangibles	200	$ 300
Goodwill	$ 1,900		$ 1,900
Trademarks
Intangible assets
Weighted - Average Amortization Period (Years)	5 years		5 years
Gross Carrying Amount	$ 1,900		$ 1,900
Accumulated Amortization	(1,014)		(918)
Net Book Value	$ 886		$ 982
Customer relationships
Intangible assets
Weighted - Average Amortization Period (Years)	5 years		5 years
Gross Carrying Amount	$ 1,300		$ 1,300
Accumulated Amortization	(693)		(628)
Net Book Value	607		672
Non-compete agreements
Intangible assets
Gross Carrying Amount	100		100
Accumulated Amortization	(89)		(81)
Net Book Value	$ 11		$ 19
Non-compete agreements | Minimum
Intangible assets
Weighted - Average Amortization Period (Years)	3 years		3 years
Non-compete agreements | Maximum
Intangible assets
Weighted - Average Amortization Period (Years)	5 years		5 years
Other intangibles
Intangible assets
Weighted - Average Amortization Period (Years)	3 years		3 years
Gross Carrying Amount	$ 373		$ 373
Accumulated Amortization	(298)		(270)
Net Book Value	$ 75		$ 103
Domain names
Intangible assets
Weighted - Average Amortization Period (Years)	5 years		5 years
Gross Carrying Amount	$ 2,687		$ 2,687
Accumulated Amortization	(2,685)		(2,685)
Net Book Value	$ 2		$ 2

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Property and equipment, net
Property and equipment, gross	$ 235,325		$ 176,201
Less accumulated depreciation and amortization	(72,731)		(63,876)
Property and equipment, net	162,594		112,325
Depreciation and amortization	10,300	$ 6,500
Furniture and computer equipment
Property and equipment, net
Property and equipment, gross	78,617		68,416
Site and software development costs
Property and equipment, net
Property and equipment, gross	55,311		50,907
Leasehold improvements
Property and equipment, net
Property and equipment, gross	30,751		29,315
Construction in progress
Property and equipment, net
Property and equipment, gross	$ 70,646		$ 27,563

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Rental expense under operating leases	$ 7.1	$ 4.1
Letter of credit issued as security for lease agreements	7		$ 5.9
Future minimum lease payments for non-cancelable lease	$ 216.7

Commitments and Contingencies33

Commitments and Contingencies (Details 2) $ in Millions	Mar. 31, 2016USD ($)
Sales and other similar tax assessments
Contingencies
Aggregate amount of claims	$ 12.9

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
2014 Plan
Equity based compensation
Number of shares authorized	8,603,066
Restricted stock units
Equity based compensation
Shares issued under plan	1,094,560
Restricted stock units | 2014 Plan
Equity based compensation
Shares issued under plan	4,192,719
Stock options
Common stock options
Outstanding at the beginning of the period (in shares)	279,591
Options exercised (in shares)	(16,772)
Outstanding at the end of the period (in shares)	262,819	279,591
Exercisable at the end of the period (in shares)	262,603
Expected to vest at the end of the period (in shares)	133
Weighted- Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 2.98
Exercised (in dollars per share)	3.10
Outstanding at the end of the period (in dollars per share)	2.97	$ 2.98
Exercisable at the end of the period (in dollars per share)	2.97
Expected to vest at the end of the period (in dollars per share)	$ 3.42
Weighted- Average Remaining Contractual Term (Years)
Outstanding at the beginning of the period	5 years 83 days	5 years 6 months
Outstanding at the end of the period	5 years 83 days	5 years 6 months
Exercisable at the end of the period	5 years 83 days
Expected to vest at the end of the period	5 years 83 days
Additional disclosures
Aggregate intrinsic value of stock options exercised	$ 0.7
Aggregate intrinsic value of stock options outstanding and repurchased	10.6
Unrecognized share-based compensation (less than)	$ 0.1
Weighted average remaining vesting term for options expected to vest	3 months 18 days

Equity-Based Compensation (De35

Equity-Based Compensation (Details 2) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)$ / sharesshares
Restricted stock
Restricted stock and units
Outstanding at the beginning of the period (in shares) | shares	1,993
Vested (in shares) | shares	(1,993)
Unvested at the end of the period (in shares) | shares	0
Expected to vest at the end of the period (in shares) | shares	0
Weighted-Average Grant-Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares	$ 4.75
Vested (in dollars per share) | $ / shares	4.75
Unvested at the end of the period (in dollars per share) | $ / shares	0
Expected to vest at the end of the period (in dollars per share) | $ / shares	$ 0
Additional information
Intrinsic value of stock vested and repurchased | $	$ 0.1
Restricted stock units
Restricted stock and units
Outstanding at the beginning of the period (in shares) | shares	5,607,867
Granted (in shares) | shares	1,094,560
Vested (in shares) | shares	(462,881)
Forfeited/cancelled (in shares) | shares	(68,726)
Unvested at the end of the period (in shares) | shares	6,170,820
Expected to vest at the end of the period (in shares) | shares	4,562,931
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	40.50
Vested (in dollars per share) | $ / shares	22.54
Forfeited/cancelled (in dollars per share) | $ / shares	31.69
Unvested at the end of the period (in dollars per share) | $ / shares	30.86
Expected to vest at the end of the period (in dollars per share) | $ / shares	$ 31.35
Additional information
Intrinsic value of stock vested | $	$ 19.5
Aggregate intrinsic value | $	266.7
Unrecognized share-based compensation | $	$ 115.3
Weighted average remaining vesting term for options expected to vest	1 year 8 months 12 days

Segment and Geographic Inform36

Segment and Geographic Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)segment	Mar. 31, 2015USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment	1
Number of reportable segments | segment	1
Net revenue
Direct Retail	$ 711,846	$ 369,396
Other	35,502	54,975
Net revenue	$ 747,348	$ 424,371

Segment and Geographic Inform37

Segment and Geographic Information (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Geographic net revenue:
Geographic net revenue	$ 747,348	$ 424,371
Geographic long-lived assets:
Geographic long-lived assets	162,594		$ 112,325
United States
Geographic net revenue:
Geographic net revenue	705,921	400,580
Geographic long-lived assets:
Geographic long-lived assets	159,038		110,042
International
Geographic net revenue:
Geographic net revenue	41,427	$ 23,791
Geographic long-lived assets:
Geographic long-lived assets	$ 3,556		$ 2,283

Income Taxes (Detail)

Income Taxes (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax expense	$ 317,000	$ 46,000
Gross unrecognized tax benefits	$ 0		$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details)	3 Months Ended	18 Months Ended
	Mar. 31, 2016vote$ / sharesshares	Mar. 31, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares
Stockholders' Equity
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock
Common stock
Common stock, shares authorized	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	46,966,564	46,966,564	45,814,237
Number of votes each holder is entitled | vote	1
Class B common stock
Common stock
Common stock, shares authorized	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	37,664,049	37,664,049	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		32,974,871
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 ($)	Mar. 31, 2016	Dec. 31, 2015	Jul. 31, 2015
Credit agreement
Borrowings outstanding	$ 0	$ 0
Revolving line of credit
Credit agreement
Maximum borrowing capacity			$ 10,000,000
Wayfair, Inc. | July 31, 2015 through September 30, 2015 | Line of credit
Credit agreement
Maximum borrowing capacity			35,000,000
Wayfair, Inc. | October 1, 2015 through February 28, 2016 | Line of credit
Credit agreement
Maximum borrowing capacity			45,000,000
Wayfair, Inc. | March 1, 2016 through July 31, 2016 | Line of credit
Credit agreement
Maximum borrowing capacity			$ 35,000,000

Net Loss per Share (Details)

Net Loss per Share (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)vote$ / sharesshares	Mar. 31, 2015USD ($)$ / sharesshares
Anti-dilutive securities
Net loss | $	$ (41,205)	$ (27,136)
Weighted average common shares used for basic and diluted net loss per share computation (in shares)	84,445,000	83,210,000
Basic and Diluted (in dollars per share) | $ / shares	$ (0.49)	$ (0.33)
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	6,433,639	4,605,181
Stock options
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	262,819	423,778
Restricted stock
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	0	21,635
Total
Anti-dilutive securities
Common stockholders outstanding that were excluded from the computation of diluted net loss per share	6,170,820	4,159,768
Class A common stock
Anti-dilutive securities
Number of votes each holder is entitled | vote	1
Class B common stock
Anti-dilutive securities
Number of votes each holder is entitled | vote	10
Written consent percentage required of class B outstanding shares for conversion to class A	66.67%
Conversion ratio	1
Net loss | $	$ (41,205)	$ (27,136)
Weighted average common shares used for basic and diluted net loss per share computation (in shares)	84,445,000
Basic and Diluted (in dollars per share) | $ / shares	$ (0.49)	$ (0.33)