COMPENSATION ARRANGEMENTS (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

The stock-based compensation expense related to stock awards issued under the Plans and acquisition-related awards are presented within the following line items of the consolidated statements of operations for the years ended December 31, 2019, 2018 and 2017 (in thousands):

	Year Ended December 31,
	2019		2018		2017
Cost of revenue	$	1,482	$	1,485	$	2,658
Marketing	5,809		6,948		7,949
Selling, general and administrative	74,324		56,288		70,343
Restructuring charges	—		—		849
Other income (expense), net	—		100		245
Total stock-based compensation expense	$	81,615	$	64,821	$	82,044

We capitalized $7.1 million, $7.4 million and $6.2 million of stock-based compensation for the years ended December 31, 2019, 2018 and 2017, in connection with internally-developed software and cloud computing arrangements.

Schedule of Restricted Stock Unit Activity

The table below summarizes restricted stock unit activity under the Plans for the year ended December 31, 2019:

	Restricted Stock Units			Weighted- Average Grant Date Fair Value (per share)
Unvested at December 31, 2018	$	26,623,432		$	4.47
Granted	28,922,775			3.44
Vested	(13,641,439		)	4.23
Forfeited	(11,364,476		)	4.10
Unvested at December 31, 2019	$	30,540,292		$	3.74

Schedule of Stock Option Activity

The table below summarizes the stock option activity for the year ended December 31, 2019:

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands) (1)
Outstanding and exercisable at December 31, 2018	$	212,787		$	1.80	1.37	$	298
Exercised	(74,875		)	0.96
Forfeited	(3,250		)	1.68
Outstanding and exercisable at December 31, 2019	$	134,662		$	1.95	0.67	$	74

(1)

The aggregate intrinsic value of options outstanding and exercisable represents the total pretax intrinsic value (the difference between the fair value of our stock on the last day of each period and the exercise price, multiplied by the number of options where the fair value exceeds the exercise price) that would have been received by the option holders had all option holders exercised their options as of December 31, 2019 and 2018, respectively.