Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of Reserved Shares of Common Stock for Issuance

At December 31, 2019, the Company had reserved shares of common stock for issuance as follows (in thousands):

	As of December 31, 2019
Common stock awards granted under equity incentive plans		15,668
Common stock awards available for issuance under the 2017 Employee Stock Purchase Plan *		2,089
Common stock awards available for issuance under the 2017 Equity Incentive Plan		16,950
Total reserved shares of common stock		34,707

Summary of Restricted Stock Unit Activity

Restricted stock unit activity for the year ended December 31, 2019 is as follows (in thousands, except per share data):

	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Balance, December 31, 2018		3,686		$	48.50
Awarded		2,228			87.60
Released		(822	)		49.26
Forfeited		(548	)		50.40
Balance, December 31, 2019 - outstanding		4,544		$	67.30

Schedule of Stock Option Activity

The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan (in thousands, except per share data):

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Weighted Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value
Balance, December 31, 2018		16,371		$	8.59		6.8		—
Granted		572			100.06		—	$	39.23
Exercised		(5,352	)		5.35		—		—
Forfeited and expired		(467	)		8.77		—		—
Balance, December 31, 2019 - outstanding		11,124		$	14.84		6.2		—	$	1,324,461
Options exercisable at December 31, 2019		6,603		$	5.84		5.1		—	$	845,590

Schedule of Share-based Compensation Expense Included in Consolidated Statements of Operations

The following table shows total stock-based compensation expense included in the accompanying Consolidated Statements of Operations for the years ended December 31, 2019, 2018 and 2017 (in thousands):

	Years Ended December 31,
	2019		2018		2017
Cost of platform revenue	$	342	$	97	$	81
Cost of player revenue		1,072		469		145
Research and development		40,036		18,538		4,714
Sales and marketing		24,179		10,459		2,817
General and administrative		19,546		8,111		3,196
Total stock-based compensation	$	85,175	$	37,674	$	10,953

Summary of Assumptions Used to Value Stock-Based Awards Granted

The assumptions used to value stock-based awards granted during the years ended December 31, 2019, 2018 and 2017 are as follows:

	Years Ended December 31,
	2019		2018		2017
Dividend rate		—		—		—
Expected term (in years)	5.0 - 6.7		5.3 - 6.8		5.3 - 6.5
Risk-free interest rate	1.35 - 2.56%		2.32 - 2.88%		1.87 - 2.25%
Expected volatility	35 - 36%		38 - 40%		39 - 44%
Fair value of common stock		—		—	$2.56 - $18.46

Convertible Preferred Stock Warrants

Summary of Assumptions Used to Value Stock-Based Awards Granted

The Company valued the convertible preferred stock warrants using the following assumptions:

	Year Ended
	December 31, 2017
Dividend rate		—
Expected term (in years)	3.0 - 9.7
Risk-free interest rate	1.5 - 2.3%
Expected volatility	44 - 51%