Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Summary of Significant Accounting Policies

Summary of financial assets and liabilities measured at fair value on a recurring basis

	At December 31, 2014				At December 31, 2013
			Total Fair				Total Fair
	Level 1		Value		Level 1		Value
Cash equivalents	$	145,284	$	145,284	$	7,726	$	7,726
Total Assets	$	145,284	$	145,284	$	7,726	$	7,726

Summary of changes in Level 3 financial instruments

	Contingent
	Consideration
Fair value at December 31, 2011	$	428
Changes in fair value		1,370
Fair value at December 31, 2012	$	1,798
Changes in fair value		95
Payments on contingent consideration		(1,893)
Fair value at December 31, 2013	$	—

Summary of changes in the allowance for doubtful accounts and sales allowances

	Year Ended
	December 31,
	2014		2013		2012
Allowances, at beginning of period	$	2,184	$	1,621	$	2,369
Charged as a reduction of revenue		4,797		6,985		6,898
Charged to bad debt expense in general and administrative expenses		373		153		668
Write-offs, net of recoveries		(5,285)		(6,575)		(8,314)
Allowances, at end of period	$	2,069	$	2,184	$	1,621

Schedule of amortization expense with respect to capitalized software development costs

Years ended December 31,
2015		8,043
2016		6,238
2017		3,477
Total amortization expense	$	17,758

Schedule of fair value of awards granted to employees using the Black Scholes option pricing model

	Year Ended
	December 31,
	2014		2013		2012
Risk-free interest rate	1.93	%	1.41	%	0.96	%
Expected term (years)	6.24		6.06		6.00
Expected volatility	58	%	61	%	60	%
Dividend yield	—		—		—

Schedule of anti-dilutive shares excluded from the calculation of diluted net loss per share attributable to common stockholders

	December 31,
	2014	2013	2012
Options to purchase common stock	25,590	18,363	15,419
Common stock warrants	3,926	5,931	5,154
Conversion of convertible preferred stock	—	2,857	—
Unvested restricted stock awards	828	55	122
Contingently redeemable shares	—	—	126
Convertible promissory notes	—	—	3,444
Total shares excluded from net loss per share attributable to common stockholders	30,344	27,206	24,265