Stock Options (Tables)

12 Months Ended

Apr. 30, 2013

Stock Option Activity

Stock option activity was as follows (number of options in thousands):

	Number of Options			Weighted Average Exercise  Price
Balance as of April 30, 2011		11,691		$	3.02
Options granted		2,932			9.41
Options exercised		(1,677	)		1.82
Options forfeited		(863	)		5.33
Balance as of April 30, 2012		12,083			4.57
Options granted		5,053			8.43
Options exercised		(4,597	)		2.45
Options forfeited		(1,710	)		7.49
Balance as of April 30, 2013		10,829		$	6.83
Options vested and exercisable as of April 30, 2013		5,481		$	4.12

Summary of Stock Options

The summary of stock options as of April 30, 2013 was as follows (number of options in thousands):

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number of Options		Weighted Average  Exercise Price		Weighted Average Remaining Contractual Life		Number of Options		Weighted Average  Exercise Price		Weighted Average Remaining Contractual Life
$0.00 - $0.03		47	$	0.00		2.13		47	$	0.00		2.13
$0.03 - $0.12		66	$	0.05		2.82		66	$	0.05		2.82
$0.16 - $0.49		110	$	0.30		3.36		110	$	0.30		3.36
$0.84 - $1.83		350	$	1.80		4.64		350	$	1.80		4.64
$2.17 - $4.13		2,778	$	2.81		6.19		2,534	$	2.79		6.08
$4.20 - $6.54		2,932	$	5.14		7.81		1,631	$	4.78		7.36
$6.58 - $12.00		2,694	$	9.28		8.92		712	$	9.20		8.43
$12.60 - $18.67		1,852	$	13.70		9.37		31	$	16.82		9.00
		10,829	$	6.83		7.73		5,481	$	4.12		6.56

Restricted Stock Activity

Restricted stock activity was as follows (number of restricted shares in thousands):

	Number  of Restricted Shares			Weighted Average Grant Date  Fair Value
Balance as of April 30, 2011		—		$	—
Restricted shares granted		16			18.67
Restricted shares vested		—			—
Restricted shares forfeited		—			—
Balance as of April 30, 2012		16		$	18.67
Restricted shares granted		1,251			11.14
Restricted shares vested		(67	)		15.59
Restricted shares forfeited		(105	)		14.71
Balance as of April 30, 2013		1,095		$	10.63

Stock Options

Assumptions Used to Estimate Fair Value of Options and Restricted Stock Using Black-Scholes Option Pricing Model

The fair value of the Company’s options was estimated at the date of grant using a Black-Scholes option pricing model with the following assumptions:

	Year Ended April 30,
	2013	2012	2011
Expected volatility	54% - 55%	55% - 58%	58% - 62%
Risk-free interest rate	0.83% - 1.40%	1.05% - 2.14%	1.75% - 2.75%
Expected term (in years)	5.94 - 6.25	5.75 - 6.25	6.00 - 6.25
Dividend yield	0%	0%	0%

Restricted Stock

Assumptions Used to Estimate Fair Value of Options and Restricted Stock Using Black-Scholes Option Pricing Model

The fair value of the Company’s ESPP was estimated at the date of grant using a Black-Scholes option pricing model with the following assumptions:

	Year Ended April 30,
	2013	2012		2011
Expected volatility	36% - 37%		—		—
Risk-free interest rate	0.10% - 0.11%		—		—
Expected term (in years)	0.50		—		—
Dividend yield	0%		—		—