Net Income (Loss) Per Share Attributable to Common Stockholders (Tables)

The computations for basic and diluted net income per share attributable to common stockholders are as follows:



	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2013			2012			2013			2012
	(in thousands)
Numerator:
Net income	$	1,309		$	1,667		$	1,579		$	1,105
Net income attributable to participating securities	(2		)	(1,252		)	(2		)	(841		)
Net income attributable to common stockholders - basic	1,307			415			1,577			264
Undistributed earnings reallocated to participating securities	1			1,249			—			839
Net income attributable to common stockholders - diluted	$	1,308		$	1,664		$	1,577		$	1,103
Denominator:
Weighted-average shares used in computing net income per share attributable to common stockholders - basic	32,088			5,843			31,789			5,540
Effect of potentially dilutive securities:
Convertible preferred stock	—			17,597			—			17,597
Common stock options	4,159			3,105			3,915			2,829
Contingently issuable shares related to an acquisition	—			—			—			6
Weighted-average shares used in computing net income per share attributable to common stockholders - diluted	36,247			26,545			35,704			25,972
Net income per share attributable to common stockholders:
Basic	$	0.04		$	0.07		$	0.05		$	0.05
Diluted	$	0.04		$	0.06		$	0.04		$	0.04

The following shares were excluded in the calculation of diluted net income per share because their inclusion would have been anti-dilutive: