Stock-Based Compensation

12 Months Ended

Dec. 31, 2011

Stock-Based Compensation [Abstract]

Stock-Based Compensation

10. Stock-Based Compensation

The Company’s 1999 Stock Option Plan and 2005 Stock Award Plan (the “Plans”) provide for the grant of stock options, restricted stock, stock appreciation rights and other equity awards to employees, consultants, officers and directors. The 2005 Stock Award Plan was adopted by the Board of Directors and stockholders in November 2005 in conjunction with the Company’s initial public offering. Under the 2005 Stock Award Plan, 7,285,482 shares have been reserved for issuance, subject to annual increases. The Plans are administered by the Compensation Committee of the Board of Directors, which has the authority, among other things, to determine which individuals receive awards pursuant to the Plans, and the terms of the awards. Stock options granted under the Plans have a 10-year term and generally vest annually over a four-year period. The Company’s outstanding equity awards include stock option awards and restricted stock awards. At December 31, 2011, 912,688 shares were available for future grants. All shares available for future grant are restricted to the 2005 Stock Award Plan.

The following table sets forth the stock-based compensation expense for equity awards recorded in the consolidated statements of operations for the years ended December 31, 2009, 2010 and 2011 (in thousands):

	Year Ended December 31,
	2009		2010		2011
Cost of revenues	$	1,453	$	1,590	$	1,575
Sales and marketing		3,753		3,253		4,126
Research and development		989		1,506		2,079
General and administration		6,697		6,453		7,135
Total	$	12,892	$	12,802	$	14,915

Stock Option Awards

The following weighted-average assumptions were used in calculating stock-based compensation for stock option awards granted during the years ended December 31, 2009, 2010 and 2011:

	Year Ended December 31,
	2009			2010			2011
Stock price volatility		62	%		59	%		57	%
Expected term (years)		6.2			6.2			6.1
Risk-free interest rate		2.5	%		2.6	%		2.2	%
Dividend yield		0	%		0	%		0	%

The summary of stock option activity for the year ended December 31, 2011 is as follows:

	Number of Options			Range of Exercise Prices		Weighted- Average Exercise Price per Share		Weighted- Average Contractual Term		Aggregate Intrinsic Value as of December 31, 2011
	(In thousands)
Balance outstanding at January 1, 2011		2,478,923		$	2.46-$35.98	$	15.09
Granted		590,147			19.02-31.03		23.67
Exercised		(1,219,643	)		2.46-26.66		15.54
Forfeited or cancelled		(92,187	)		14.81-26.66		17.29
Balance outstanding at December 31, 2011		1,757,240		$	2.46-35.98	$	17.54		7.2	$	10,020
Vested and expected to vest at December 31, 2011		1,702,267		$	2.46-35.98	$	17.42		7.2	$	9,871
Balance exercisable at December 31, 2011		694,273		$	2.46-35.98	$	13.78		4.7	$	6,503

The weighted-average grant date fair value of stock options granted during the years ended December 31, 2009, 2010 and 2011 was $10.17, $9.10 and $13.03, respectively. The aggregate fair value of stock options that vested during the years ended December 31, 2009, 2010 and 2011 was $5,355,000, $3,137,000 and $4,846,000, respectively. As of December 31, 2011, $9,627,000 of total unrecognized stock-based compensation cost is related to nonvested stock option awards and is expected to be recognized over a weighted-average period of 2.9 years.

The aggregate intrinsic value in the table above represents the difference between the exercise price of the underlying equity awards and the quoted closing price of the Company’s common stock at the last day of the year multiplied by the number of shares that would have been received by the stock option holders had all holders exercised their stock options on the last day of each respective year. The aggregate intrinsic value of options exercised during the years ended December 31, 2009, 2010 and 2011 was $2,092,000, $3,992,000 and $15,548,000, respectively.

The following details the outstanding stock options at December 31, 2011:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Outstanding as of 12/31/11		Weighted- Average Remaining Contractual Term		Weighted- Average Exercise Price per Share		Exercisable as of 12/31/11		Weighted- Average Exercise Price per Share
$ 2.46 - $ 8.99		29,460		2.99	$	4.69		29,460	$	4.69
$ 9.00 - $14.22		408,390		3.96		9.16		408,390		9.16
$14.23 - $14.80		365,112		8.16		14.40		16,062		14.39
$14.81 - $22.50		322,341		7.21		18.40		156,071		19.13
$22.51 - $25.79		467,647		9.23		23.68		—		—
$25.80 - $35.98		164,290		8.10		28.51		84,290		29.29
		1,757,240		7.20	$	17.54		694,273	$	13.78

Restricted Stock Awards

The fair value of the restricted stock awards is determined based on the quoted closing market price of the Company’s common stock on the grant date.

The summary of restricted stock award activity for the year ended December 31, 2011 is as follows:

	Number of Shares Underlying Stock Awards			Weighted-Average Grant Date Fair Value
Balance nonvested at January 1, 2011		1,418,731		$	18.50
Awarded		415,471			23.49
Vested		(499,025	)		19.76
Forfeited		(52,854	)		20.47
Balance nonvested at December 31, 2011		1,282,323		$	19.55

As of December 31, 2011, $16,669,000 of total unrecognized stock-based compensation cost is related to nonvested shares of restricted stock and is expected to be recognized over a weighted-average period of 2.3 years.