Consolidated Statements of Operations (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Revenue	$ 110,391,000	$ 63,174,000	$ 29,664,000
Cost of revenue	21,802,000	10,780,000	5,078,000
Gross profit	88,589,000	52,394,000	24,586,000
Operating expenses:
Research and development	24,024,000	16,496,000	8,565,000
Sales and marketing	89,162,000	58,156,000	28,365,000
General and administrative	25,319,000	17,178,000	10,053,000
Total operating expenses	138,505,000	91,830,000	46,983,000
Loss from operations	(49,916,000)	(39,436,000)	(22,397,000)
Other income (expense):
Interest income	176,000	16,000	9,000
Interest expense	(104,000)	(64,000)	(48,000)
Other expense, net	(390,000)	(741,000)	(105,000)
Loss before income taxes	(50,234,000)	(40,225,000)	(22,541,000)
Benefit from income taxes	(85,000)	0	0
Net loss	$ (50,149,000)	$ (40,225,000)	$ (22,541,000)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.98)	$ (2.58)	$ (1.49)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted	25,290	15,596	15,096