7. Consolidated Balance Sheet Components

Allowance for Doubtful Accounts

The allowance for doubtful accounts is comprised of the following activity (in thousands):

	Years Ended December 31,
	2016			2015			2014
Allowance for doubtful accounts and sales returns reserve, beginning balance	$	1,438		$	215		$	410

Allowance for doubtful accounts, beginning balance	$	1,115		$	215		$	410
Charged to costs and expenses, net of recoveries		315			1,044			418
Deductions (write-offs)		(477	)		(144	)		(613	)
Allowance for doubtful accounts, ending balance		953			1,115			215
Sales returns reserve, beginning balance		323
Charged to revenue		1,560			677			-
Deductions (write-offs)		(1,052	)		(354	)		-
Sales returns reserve, ending balance		831			323			-
Total allowance for doubtful accounts and sales returns reserve, ending balance	$	1,784		$	1,438		$	215

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):

	As of December 31,
	2016		2015
Prepaid expenses		4,980		5,111
Prepaid income taxes		1,559		585
Interest receivable		758		467
Other		625		1,802
Total prepaid expenses and other current assets	$	7,922	$	7,965

Property and Equipment, net

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

	As of December 31,
	2016			2015
Computers and related equipment	$	25,285		$	15,953
Office furniture and equipment		3,228			1,632
Leasehold improvements		11,947			7,791
Total property and equipment		40,460			25,376
Less: accumulated depreciation and amortization		(18,964	)		(13,212	)
Total property and equipment, net	$	21,496		$	12,164

Depreciation and amortization expense totaled $7.5 million, $4.5 million and $3.6 million, for the years ended December 31, 2016, 2015 and 2014, respectively.

Accrued Compensation and Benefits

Accrued compensation and benefits consist of the following (in thousands):

	As of December 31,
	2016		2015
Salary and related benefits	$	9,588	$	7,215
Accrued vacation		4,178		3,774
Accrued incentive payments		5,942		9,270
Accrued restructuring		1,132		-
Total accrued compensation and benefits	$	20,840	$	20,259

Accrued and Other Current Liabilities

Accrued and other current liabilities consist of the following (in thousands):

	As of December 31,
	2016		2015
Accrued expenses	$	4,616	$	4,633
Derivative liability		639		595
Income tax payable		435		323
Short-term deferred rent		461		283
Skyfence holdback liability		-		7,556
Sales Taxes Payable		849		411
Other		683		482
Total accrued and other current liabilities	$	7,683	$	14,283

Other Liabilities

Other long-term liabilities consist of the following (in thousands):

	As of December 31,
	2016		2015
Long-term deferred rent	$	2,111	$	1,926
Deferred tax liability		1,265		1,145
Uncertain Tax Positions		2,446		1,236
Other		815		208
Total other liabilities	$	6,637	$	4,515