Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2013

Summary of Property and Equipment Useful Life

Property and equipment, net, are stated at cost, subject to review of impairment, and depreciated using the straight-line method over the estimated useful lives of the assets as follows:



Computer equipment and software		3—5 years
Furniture and fixtures		3—5 years
Leasehold improvements		shorter of the lease term or estimated useful life

When assets are sold, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expenses. Repairs and maintenance are charged to operations as incurred.

Property and equipment, net consists of the following (in thousands):



	December 31,
	2013			2012
Computer equipment and software	$	90,617		$	46,541
Furniture and fixtures	13,751			4,691
Leasehold improvements	8,371			2,649
Construction in progress	928			4,855
	113,667			58,736
Less: Accumulated depreciation	(38,107		)	(16,394		)
Total property and equipment, net	$	75,560		$	42,342

Changes in Allowance for Doubtful Accounts

The following table presents the changes in the allowance for doubtful accounts (in thousands):



	Balance at Beginning of Year		Additions: Charged to Operations		Additions: Charged to Deferred Revenue	Less: Write-offs	Balance at End of Year
Year ended December 31, 2013
Allowance for doubtful accounts	$	742	(43	)	946	502	$	1,143
Year ended December 31, 2012
Allowance for doubtful accounts	$	—	570		172	—	$	742

Service Level Credits

The following table presents the changes in the service level credit accrual (in thousands):



	Balance at Beginning of Year		Additions: Charged against revenue	Less: Usage	Balance at End of Year
Year ended December 31, 2013
Service level credit accrual	$	1,196	430	978	$	648
Year ended December 31, 2012
Service level credit accrual	$	250	1,574	628	$	1,196