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

	Years ended December 31,

	2011		2010		2009
	(in thousands)
Numerator:
Net income (loss) attributable to common stockholders, basic	$	4,662	$	10,554	$	(4,511	)
Accretion of convertible preferred stock		—		5,020		—

Net income (loss) attributable to Boingo Wireless, Inc., diluted	$	4,662	$	15,574	$	(4,511	)

Denominator:
Weighted average common stock, basic		24,014		5,834		5,801
Effect of dilutive convertible preferred stock		—		22,846		—
Effect of dilutive stock options		3,457		3,204		—
Effect of dilutive common stock warrants		10		15		—

Weighted average common stock, diluted		27,481		31,899		5,801

Net income (loss) per share attributable to common stockholders:
Basic	$	0.19	$	1.81	$	(0.78	)
Diluted	$	0.17	$	0.49	$	(0.78	)

The following outstanding securities were not included in the computation of diluted net income (loss) per share as the inclusion would have been anti-dilutive for the periods indicated:

	Years ended December 31,

	2011		2010		2009
	(in thousands)
Convertible preferred stock using the if-converted method		7,699		—		22,846
Stock options, out-of-the-money using the treasury stock method		2,172		—		5,281
Common stock warrants		—		—		26
Preferred stock warrants		26		26		26

Total		9,897		26		28,179