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

Basic 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 during the period. In computing diluted net income (loss) attributable to common stockholders, 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 or there is no income attributable to common stockholders, 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 (on a one-to-one basis) 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,
	2016									2015
	Class			Class			Class			Class		Class		Class
	A			B			C			A		B		C
	(unaudited)
BASIC:
Net income (loss) attributable to common stockholders	$	(36,203	)	$	(4,564	)	$	(970	)	$	2,607	$	377	$	68
Weighted-average common shares outstanding		765,403			96,488			20,517			786,768		113,831		20,517
Basic net income (loss) per share	$	(0.05	)	$	(0.05	)	$	(0.05	)	$	0.00	$	0.00	$	0.00
DILUTED:
Net income (loss) attributable to common stockholders	$	(36,203	)	$	(4,564	)	$	(970	)	$	2,607	$	377	$	68
Reallocation of net income (loss) as a result of conversion of Class C shares to Class A shares		(970	)		—			—			68		—		—
Reallocation of net income (loss) as a result of conversion of Class B shares to Class A shares		(4,564	)		—			—			377		—		—
Reallocation of net income (loss) to Class B and Class C shares											—		27		(1	)
Net income (loss) attributable to common stockholders-diluted	$	(41,737	)	$	(4,564	)	$	(970	)	$	3,052	$	404	$	67
Weighted-average common shares outstanding-basic		765,403			96,488			20,517			786,768		113,831		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		96,488			—			—			113,831		—		—
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		882,408			96,488			20,517			940,032		124,340		20,517
Diluted net income (loss) per share	$	(0.05	)	$	(0.05	)	$	(0.05	)	$	0.00	$	0.00	$	0.00

	Nine Months Ended September 30,
	2016									2015
	Class			Class			Class			Class			Class			Class
	A			B			C			A			B			C
	(unaudited)
BASIC:
Net income (loss) attributable to common stockholders	$	(62,306	)	$	(8,731	)	$	(1,704	)	$	(59,922	)	$	(8,806	)	$	(1,584	)
Weighted-average common shares outstanding		750,038			105,101			20,517			775,926			114,026			20,517
Basic net income (loss) per share	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)
DILUTED:
Net income (loss) attributable to common stockholders	$	(62,306	)	$	(8,731	)	$	(1,704	)	$	(59,922	)	$	(8,806	)	$	(1,584	)
Reallocation of net income (loss) as a result of conversion of Class C shares to Class A shares		(1,704	)		—			—			(1,584	)		—			—
Reallocation of net income (loss) as a result of conversion of Class B shares to Class A shares		(8,731	)		—			—			(8,806	)		—			—
Net income (loss) attributable to common stockholders-diluted	$	(72,741	)	$	(8,731	)	$	(1,704	)	$	(70,312	)	$	(8,806	)	$	(1,584	)
Weighted-average common shares outstanding-basic		750,038			105,101			20,517			775,926			114,026			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		105,101			—			—			114,026			—			—
Weighted-average common shares outstanding-diluted		875,656			105,101			20,517			910,469			114,026			20,517
Diluted net income (loss) per share	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)	$	(0.08	)

The following weighted-average equity awards were excluded from the computation 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,
	2016		2015		2016		2015
Stock options and employee stock purchase plan		29,814		9,308		25,817		30,974
Restricted shares		3,344		7,791		4,165		9,102
ZSUs		62,587		40,445		62,850		64,056
Total		95,745		57,544		92,832		104,132