Stock Based Awards and Other Equity Instruments (Tables)

12 Months Ended

Dec. 31, 2023

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Amount of Stock-Based Compensation Expense Related to Income Tax Benefit

The following table presents the amount of stock-based compensation expense and the related income tax benefit included in our consolidated statements of operations during the periods presented:

	Year ended December 31,
	2023			2022			2021
	(in millions)
Cost of revenue	$	1		$	1		$	1
Selling and marketing		16			12			16
Technology and content		40			36			46
General and administrative		39			39			57
Total stock-based compensation expense		96			88			120
Income tax benefit from stock-based compensation expense		(21	)		(18	)		(23	)
Total stock-based compensation expense, net of tax effect	$	75		$	70		$	97

Summary of Stock Option Activity

A summary of our stock option activity, consisting of service-based non-qualified stock options, is presented below:

				Weighted		Weighted
				Average		Average
				Exercise		Remaining		Aggregate
	Options			Price Per		Contractual		Intrinsic
	Outstanding			Share		Life		Value
	(in thousands)					(in years)		(in millions)
Options outstanding as of December 31, 2022		5,462		$	43.48
Granted		164		$	20.15
Cancelled or expired (1)		(1,699	)	$	59.54
Options outstanding as of December 31, 2023		3,927		$	35.56		5.2	$	2
Exercisable as of December 31, 2023		2,893		$	39.30		4.1	$	1
Vested and expected to vest after December 31, 2023 (2)		3,781		$	35.88		5.1	$	2

(1)Inclusive of 1,100,000 stock options awarded in August 2013 to our former CEO, Stephen Kaufer, that expired during the third quarter of 2023. The expiration of these stock options had no impact to our stock-based compensation expense under GAAP during the third quarter of 2023.

(2)The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our vested and expected to vest calculation unless necessary for a performance condition award.

Weighted-Average Assumptions of Estimated Fair Value of Stock Option Grants

The fair value of stock option grants has been estimated at the date of grant using the Black–Scholes option pricing model with the following weighted average assumptions for the periods presented:

	December 31,
	2023			2022			2021
Risk free interest rate		3.70	%		3.07	%		0.83	%
Expected term (in years)		5.16			5.42			5.45
Expected volatility		53.43	%		51.63	%		49.61	%
Expected dividend yield	—  %			—  %			—  %
Weighted-average grant date fair value	$	10.18		$	9.93		$	18.40

Summary of RSU Activity

A summary of our RSU activity, consisting of service-based vesting terms, is presented below:

				Weighted
				Average
				Grant-		Aggregate
	RSUs			Date Fair		Intrinsic
	Outstanding			Value Per Share		Value
	(in thousands)					(in millions)
Unvested RSUs outstanding as of December 31, 2022		8,572		$	28.41
Granted		8,043			20.80
Vested and released (1)		(3,688	)		29.62
Cancelled		(1,407	)		25.59
Unvested RSUs outstanding as of December 31, 2023 (2)		11,520		$	23.06	$	248

(1)Inclusive of approximately 840,000 RSUs withheld due to net share settlement to satisfy required employee tax withholding requirements. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2023 Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the consolidated statements of cash flows.

(2)The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our vested and expected to vest calculation unless necessary for a performance condition award.

PSUs and MSUs

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of RSU Activity

A summary of our performance-based RSUs ("PSUs") and market-based RSUs (“MSUs”) activity is presented below:

	PSUs (1)							MSUs (2)
				Weighted							Weighted
				Average							Average
				Grant-		Aggregate					Grant-		Aggregate
				Date Fair		Intrinsic					Date Fair		Intrinsic
	Outstanding			Value Per Share		Value		Outstanding			Value Per Share		Value
	(in thousands)					(in millions)		(in thousands)					(in millions)
Unvested and outstanding as of December 31, 2022		—		$	—				592		$	10.00
Granted		546			18.45				34			14.80
Cancelled		(27	)		18.45				(54	)		9.26
Unvested and outstanding as of December 31, 2023		519		$	18.45	$	11		572		$	10.35	$	12

(1)Represents PSUs awarded in February 2023. The PSU awards provide for vesting in two equal annual installments on each of December 31, 2024 and December 31, 2025, based on the extent to which the Company achieves certain financial metrics relative to targets established by the Company’s Compensation Committee of its Board of Directors. The estimated grant-date fair value per PSU was measured based on the quoted price of our common stock at the date of grant, calculated upon the establishment of performance targets, and will be amortized on a straight-line basis over the requisite service period. Based upon actual attainment relative to the target financial metrics, employees have the ability to receive up to 200% of the target number originally granted, or to be issued none at all. Probable outcome for performance-based awards is updated based upon changes in actual and forecasted operating results or expected achievement of performance goals, as applicable, and the impact of modifications, if any.

(2)MSUs shall vest three years from grant date, generally with 25% vesting if the weighted-average stock price over a 30-day trading period during the vesting period is equal to or greater than $35.00 but less than $45.00, 50% vesting if equal to or greater than $45.00 but less than $55.00, and 100% vesting if equal to or greater than $55.00, subject to continuous employment with, or performance of services for, the Company. A Monte-Carlo simulation model, which simulated the present value of the potential outcomes of future stock prices was used to calculate the grant-date fair value of our MSU awards. The estimated grant-date fair value of these awards is amortized on a straight-line basis over the requisite service period and is not adjusted based on the actual number of awards that ultimately vest.