11. Net Income (Loss) Per Share of Common Stock

Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period. In computing diluted net income (loss) per share, net income (loss) is re-allocated to reflect the potential impact of dilutive securities, including stock options, warrants, unvested restricted stock and unvested ZSUs. Diluted net income (loss) per share is computed by dividing net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding, including potential dilutive securities. For periods in which we have generated a net loss, we do not include stock options, warrants, unvested restricted stock and unvested ZSUs in our computation of diluted net income (loss) per share, as the impact of these awards is anti-dilutive. The net per share amounts are the same for Class A, Class B and Class C common stock because the holders of each class are legally entitled to equal per share distributions whether through dividend or distribution. Further, as we assume the conversion of Class B and Class C common shares into Class A common shares for the Class A diluted net income (loss) per share computation, the net income (loss) is equal to total net income (loss) for that computation.

The following table sets forth the computation of basic and diluted net income (loss) per share of common stock (in thousands, except per share data):


	Three Months Ended September 30,
	2015							2014
	Class		Class		Class			Class			Class			Class
	A		B		C			A			B			C
	(unaudited)
BASIC:
Net income (loss) attributable to common stockholders	$	2,607		377		68		$	(48,121	)	$	(7,613	)	$	(1,324	)
Weighted-average common shares outstanding		786,768		113,831		20,517			745,558			117,946			20,517

Basic net income (loss) per share	$	0.00	$	0.00	$	0.00		$	(0.06	)	$	(0.06	)	$	(0.06	)

DILUTED:
Net income (loss) attributable to common stockholders	$	2,607		377		68		$	(48,121	)	$	(7,613	)	$	(1,324	)
Reallocation of net income (loss) as a result of conversion of Class C shares to Class A shares		68		—		—			(1,324	)		—			—
Reallocation of net income (loss) as a result of conversion of Class B shares to Class A shares		377		—		—			(7,613	)		—			—
Reallocation of net income (loss) to Class B and Class C shares		—		27		(1	)		—			—			—

Net income (loss) attributable to common stockholders-diluted	$	3,052	$	404	$	67		$	(57,058	)	$	(7,613	)	$	(1,324	)

Weighted-average common shares outstanding-basic		786,768		113,831		20,517			745,558			117,946			20,517
Conversion of Class C to Class A common shares		20,517		—		—			20,517			—			—
Conversion of Class B to Class A common shares		113,831		—		—			117,946			—			—

Weighted-average effect of dilutive securities:
Stock options and employee stock purchase plan		11,994		10,446		—			—			—			—
ZSUs		6,922		63		—			—			—			—

Weighted-average common shares outstanding-diluted		940,032		124,340		20,517			884,021			117,946			20,517

Diluted net income (loss) per share	$	0.00	$	0.00	$	0.00		$	(0.06	)	$	(0.06	)	$	(0.06	)


	Nine Months Ended September 30,
	2015									2014
	Class			Class			Class			Class			Class			Class
	A			B			C			A			B			C
	(unaudited)
BASIC:
Net income (loss) attributable to common stockholders	$	(59,922	)	$	(8,806	)	$	(1,584	)	$	(151,292	)	$	(25,215	)	$	(4,267	)
Weighted-average common shares outstanding		775,926			114,026			20,517			727,425			121,236			20,517

Basic net income per share	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.21	)	$	(0.21	)	$	(0.21	)

DILUTED:
Net income (loss) attributable to common stockholders	$	(59,922	)	$	(8,806	)	$	(1,584	)	$	(151,292	)	$	(25,215	)	$	(4,267	)
Reallocation of net income (loss) as a result of conversion of Class C shares to Class A shares		(1,584	)		—			—			(4,267	)		—			—
Reallocation of net income (loss) as a result of conversion of Class B shares to Class A shares		(8,806	)		—			—			(25,215	)		—			—

Net income (loss) attributable to common stockholders-diluted	$	(70,312	)	$	(8,806	)	$	(1,584	)	$	(180,774	)	$	(25,215	)	$	(4,267	)

Weighted-average common shares outstanding-basic		775,926			114,026			20,517			727,425			121,236			20,517
Conversion of Class C to Class A common shares outstanding		20,517			—			—			20,517			—			—
Conversion of Class B to Class A common shares outstanding		114,026			—			—			121,236			—			—

Number of shares used in diluted net income (loss) per share		910,469			114,026			20,517			869,178			121,236			20,517

Diluted net income (loss) per share	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.21	)	$	(0.21	)	$	(0.21	)

The following weighted-average equity awards were excluded from the calculation of diluted net income (loss) per share because their effect would have been anti-dilutive for the periods presented (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Stock options and employee stock purchase plan		9,308		42,726		30,974		43,206
Restricted shares		7,791		13,763		9,102		12,333
ZSUs		40,445		51,550		64,056		56,484

Total		57,544		108,039		104,132		112,023