12. Net (loss) income per share attributable to common stockholders

The following table sets forth the computation of basic and diluted net (loss) income per share attributable to common stockholders:

	Three Months Ended June 30,					Six Months Ended June 30,
	2013			2012		2013			2012
	(in thousands)
Numerator:
Net (loss) income attributable to common stockholders, basic and diluted	$	(399	)	$	1,461	$	(1,520	)	$	3,118
Denominator:
Weighted average common stock, basic	35,670			34,799		35,634			34,384
Dilutive effect of stock-based awards	—			2,604		—			2,937
Weighted average common stock, dilutive	35,670			37,403		35,634			37,321
Net (loss) income per share attributable to common stockholders:
Basic	$	(0.01	)	$	0.04	$	(0.04	)	$	0.09
Diluted	$	(0.01	)	$	0.04	$	(0.04	)	$	0.08

For the three and six months ended June 30, 2013, we excluded all stock options and RSUs from the computation of diluted net loss per share due to the net loss for the period. For the three and six months ended June 30, 2012, 2,409,925 and 2,391,117, respectively, options to purchase common stock were not included in the computation of diluted net income per share as the inclusion would have been anti-dilutive.