The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Costs and expenses:
Amortization adjustment	$ 17	$ 18	$ 33	$ 35
Stock-based compensation:
Stock-based compensation	32	25	61	51
Cost of Revenue
Stock-based compensation:
Stock-based compensation			1	1
Selling and Marketing
Stock-based compensation:
Stock-based compensation	4	4	8	7
Technology and Content
Stock-based compensation:
Stock-based compensation	13	9	24	20
General and Administrative
Stock-based compensation:
Stock-based compensation	15	12	28	23
Acquired Technology
Costs and expenses:
Amortization of intangible assets	1	1	1	1
Website Development Costs
Costs and expenses:
Depreciation	$ 16	$ 17	$ 32	$ 34