Stock-Based Compensation (Tables)

3 Months Ended

Apr. 30, 2015

Summary of Stock Option Activity Under Equity Incentive Plans and Related Information

The following table summarizes the stock option activity under the equity incentive plans and related information:

	Shares Subject to Options Outstanding					Weighted-Average
	Shares Subject to			Weighted-		Remaining
	Outstanding			Average Exercise		Contractual Life		Aggregate
	Options			Price		(Years)		Intrinsic Value
								(in thousands)
Balance as of January 31, 2015		17,465,571		$	5.67		7.80	$	229,713
Options granted		342,980			17.54
Option exercised		(350,096	)		3.09
Options forfeited/cancelled		(563,225	)		6.92
Balance as of April 30, 2015		16,895,230		$	5.92		7.60	$	190,236
Vested and expected to vest as of April 30, 2015		16,628,973		$	5.85		7.58	$	188,405
Exercisable as of April 30, 2015		8,924,686		$	3.50		6.98	$	121,735

Summary of Components of Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the consolidated statements of operations (in thousands):

	Three Months Ended
	April 30,
	2015		2014
Cost of revenue	$	851	$	226
Research and development		5,263		2,008
Sales and marketing		4,283		2,065
General and administrative		2,318		1,453
Net loss attributable to common stockholders	$	12,715	$	5,752

Summary of Estimated Fair Value of Employee Stock Options

We estimated the fair value of employee stock options and ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions:

	Three Months Ended
	April 30,
	2015					2014
Employee Stock Options
Expected term (in years)		6.0		-	6.1	5.7	-	6.1
Risk-free interest rate		1.6	%	-	1.7%				2.1%
Volatility		43	%	-	44%				49%
Dividend yield					0%			0%
Employee Stock Purchase Plan
Expected term (in years)	0.5			-	2.0				—
Risk-free interest rate		0.2	%	-	0.7%				—
Volatility		39	%	-	41%				—
Dividend yield					0%				—

Restricted Stock Units

Summary of Restricted Stock Unit Activity Under Equity Incentive Plans and Related Information

The following table summarizes the restricted stock unit activity under the equity incentive plans and related information:

	Number of			Weighted-
	Restricted			Average
	Stock Units			Grant Date
	Outstanding			Fair Value
Unvested balance - January 31, 2015		4,939,709		$	15.66
Granted		2,673,044			17.54
Vested, net of shares withheld for employee payroll taxes		(348,962	)		17.77
Forfeited/cancelled, including shares withheld for employee payroll taxes		(430,831	)		17.17
Unvested balance - April 30, 2015		6,832,960		$	16.19

Restricted Stock

Summary of Restricted Stock Award Activity Under Equity Incentive Plans and Related Information

The following table summarizes the restricted stock activity under the equity incentive plans and related information:

	Number of			Weighted-
	Restricted			Average
	Stock			Grant Date
	Outstanding			Fair Value
Unvested balance - January 31, 2015		172,661		$	9.60
Granted		23,364			17.54
Vested		(21,516	)		14.99
Forfeited/cancelled, including shares withheld for employee payroll taxes		(7,790	)		17.54
Unvested balance - April 30, 2015		166,719		$	9.65