Stock-based compensation (Tables)

6 Months Ended

Dec. 31, 2012

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

Stock Option Activity

Stock option activity for the six months ended December 31, 2012 was as follows (in thousands):

	Number of Shares
Options outstanding as of June 30, 2012	7,707
Granted	1,027
Exercised	(753	)
Canceled	(576	)
Options outstanding as of December 31, 2012	7,405

Information regarding stock options outstanding at December 31, 2012 is summarized below:

	Number of Shares (thousands)	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (thousands)
Options outstanding	7,405	$	5.89	6.93	$	18,886
Options vested and expected to vest	7,053	$	5.82	6.87	$	18,512
Options exercisable	3,773	$	4.64	5.53	$	14,364

Stock-Based Compensation Expense

The following table summarizes the stock-based compensation expense recorded for stock options, restricted stock units and restricted common stock issued to employees and nonemployees (in thousands):

	Three Months Ended				Six Months Ended
	December 31,				December 31,
	2012		2011		2012		2011
Cost of revenue	$	39	$	21	$	76	$	48
Research and development	889		638		1,528		1,240
Selling and marketing	633		319		992		534
General and administrative	616		334		1,001		670
Total stock-based compensation expense	$	2,177	$	1,312	$	3,597	$	2,492

Assumptions Used to Estimate Weighted Average Fair Value of Options

The weighted average assumptions used to value stock-based awards granted were as follows:

	Three Months Ended				Six Months Ended
	December 31,				December 31,
	2012		2011		2012		2011
Expected volatility	73	%	65	%	73	%	63	%
Expected term (in years)	4.76		4.50		4.80		4.50
Risk-free interest rate	0.71	%	0.96	%	0.69	%	0.96	%
Dividend yield	—		—		—		—