STOCKHOLDERS' EQUITY (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

A summary of stock option activity for the six months ended June 30, 2016 is as follows (in thousands, except share and per share data):



	Number of Stock Options Outstanding		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance as of December 31, 2015	107,515,554		$	6.99	7.87	$	656,194
Granted	1,707,320		13.54
Exercised	(4,225,876	)	1.91
Forfeited	(5,993,756	)	$	11.26
Balance as of June 30, 2016	99,003,242		7.06		7.57	307,645
Options vested and expected to vest as of
June 30, 2016	92,406,077		6.79		6.88	303,773
Options exercisable as of
June 30, 2016	94,552,296		6.89		7.47	307,645

Schedule of RSU Activity

Activity related to RSUs during the six months ended June 30, 2016 is set forth below:



	Number of RSUs		Weighted Average Grant Date Fair Value
Unvested as of December 31, 2015	3,632,765		$	13.14
Granted	12,649,921		12.43
Vested	(754,643	)	12.38
Forfeited	(550,261	)	13.53
Unvested as of June 30, 2016	14,977,782		$	12.56

Schedule of Fair Value Assumptions for Options

The fair value of stock options granted was estimated using the following weighted-average assumptions:



	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
Dividend yield	—	%	—	%	—	%	—	%
Risk-free interest rate	1.55	%	1.80	%	1.55	%	1.74	%
Expected volatility	42.71	%	46.27	%	42.71	%	48.63	%
Expected term (years)	6.08		6.08		6.08		6.10

Summary of the Effect of Share-Based Compensation on the Condensed Consolidated Statement of Operations

The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
Product development	$	24,168	$	10,391	$	46,115	$	19,349
Sales and marketing	3,363		1,345		6,266		2,774
General and administrative	9,391		3,496		15,739		6,570
Total	$	36,922	$	15,232	$	68,120	$	28,693