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 Company's operating and reportable segments are U.S. and International. These segments reflect the way the CODM allocates resources and evaluates financial performance, which is based upon each segment's Adjusted EBITDA. Adjusted EBITDA is defined as loss before depreciation and amortization, equity-based compensation and related taxes, interest and other income and expense, provision for income taxes, and non-recurring items. These charges are excluded from evaluation of segment performance because it facilitates reportable segment performance comparisons on a period-to-period basis.

The Company allocates certain operating expenses to the operating and reportable segments, including "Customer service and merchant fees" and "Selling, operations, technology, general and administrative" based on the usage and relative contribution provided to the segments. It excludes from the allocations certain operating expense lines, including "Depreciation and amortization," "Equity-based compensation and related taxes," "Interest expense, net," "Other (income), net," and "Provision for income taxes." There are no revenue transactions between the Company's reportable segments.

The U.S. segment primarily consists of amounts earned through product sales through the Company's five distinct sites in the U.S. and through websites operated by third parties in the U.S.

The International segment primarily consists of amounts earned through product sales through the Company's international sites.

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 U.S. provided greater than 10% of total revenue.

The following tables present Direct Retail and Other net revenues and Adjusted EBITDA attributable to the Company's reportable segments for the periods presented (in thousands):



	Three months ended September 30,				Nine months ended September 30,
	2019		2018		2019		2018
U.S. Direct Retail	$	1,960,847	$	1,460,056	$	5,593,923	$	4,043,270
U.S. Other	5,807		13,189		30,947		42,903
U.S. segment net revenue	1,966,654		1,473,245		5,624,870		4,086,173
International Direct Retail	338,833		232,400		968,697		678,997
International segment net revenue	338,833		232,400		968,697		678,997
Total net revenue	$	2,305,487	$	1,705,645	$	6,593,567	$	4,765,170



	Three months ended September 30,						Nine months ended September 30,
	2019			2018			2019			2018
Adjusted EBITDA:
U.S.	$	(62,878	)	$	(26,036	)	$	(91,002	)	$	(26,774	)
International	(81,306		)	(50,369		)	(225,383		)	(134,400		)
Total reportable segments Adjusted EBITDA	(144,184		)	(76,405		)	(316,385		)	(161,174		)
Less: reconciling items (1)	(127,851		)	(75,321		)	(337,977		)	(199,061		)
Net loss	$	(272,035	)	$	(151,726	)	$	(654,362	)	$	(360,235	)

(1) Adjustments are made to reconcile total reportable segments Adjusted EBITDA to consolidated net loss including the following (in thousands):



	Three months ended September 30,						Nine months ended September 30,
	2019			2018			2019			2018
Depreciation and amortization	$	50,250		$	32,544		$	134,172		$	87,426
Equity-based compensation and related taxes	65,275			36,317			173,963			95,074
Interest expense, net	14,432			7,066			33,922			18,269
Other (income), net	(2,182		)	(1,054		)	(5,582		)	(2,661		)
Provision for income taxes	76			448			1,502			953
Total reconciling items	$	127,851		$	75,321		$	337,977		$	199,061

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 websites operated by third parties and fees from our media solutions business (in thousands):



	Three months ended September 30,				Nine months ended September 30,
	2019		2018		2019		2018
Net revenue
Direct Retail	$	2,299,680	$	1,692,456	$	6,562,620	$	4,722,267
Other	5,807		13,189		30,947		42,903
Net revenue	$	2,305,487	$	1,705,645	$	6,593,567	$	4,765,170

The following table presents total assets attributable to the Company's reportable segments reconciled to consolidated amounts (in thousands):



	September 30, 2019		December 31, 2018
Assets by segment
U.S.	$	1,482,542	$	670,344
International	190,498		56,177
Total reportable segments assets	1,673,040		726,521
Plus: reconciling corporate assets	1,334,595		1,164,329
Total assets	$	3,007,635	$	1,890,850

U.S. and International segment assets consist primarily of "Accounts receivable," "Inventories," "Prepaid expenses and other current assets," "Property and equipment, net" and "Operating lease right-of-use assets." Corporate assets include "Cash and cash equivalents," marketable securities, "Long-term investments," corporate facilities, "Goodwill and intangible assets, net," and capitalized internal-use software and website development costs.