v3.6.0.2
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Cash flows from operating activities      
Net loss $ (36,911) $ (44,218) $ (29,037)
Adjustments to reconcile net loss to net cash used in operating activities:      
Depreciation and amortization 3,534 3,548 2,349
Stock-based compensation 21,702 18,371 10,252
Remeasurement of convertible preferred stock warrant liability 0 0 (90)
Others 278 378 178
Changes in operating assets and liabilities:      
Accounts receivable, net (3,366) 1,871 (7,115)
Inventories (1,854) (2,415) (1,544)
Prepaid expenses and other current assets 2,081 (2,485) (1,255)
Other assets 80 (1,024) (1,094)
Accounts payable (4,522) 5,237 1,295
Accrued liabilities (2,643) 3,067 1,563
Other liabilities 425 (394) 165
Deferred revenue 6,642 13,107 15,585
Net cash used in operating activities (14,554) (4,957) (8,748)
Cash flows from investing activities      
Purchases of property and equipment (2,161) (2,270) (2,385)
Capitalized software development costs 0 (1,913) (4,364)
Maturities and sales of short-term investments 50,761 2,498 0
Purchases of short-term investments (46,824) (49,223) 0
Payments to Acquire Investments (1,500)    
Net cash provided by (used in) investing activities 276 (50,908) (6,749)
Cash flows from financing activities      
Proceeds from initial public offering, net of underwriting discounts 0 0 80,213
Payment of offering costs 0 0 (4,007)
Proceeds from exercise of convertible preferred stock warrants 0 0 907
Proceeds from exercise of vested stock options 870 1,524 1,721
Proceeds from employee stock purchase plan 5,326 5,196 0
Payment for shares withheld for tax withholdings on vesting of restricted stock units (1,121) (3,158) (316)
Payments to repurchase common stock (2,139)    
Payments on capital lease obligation (53)    
Proceeds from issuance of debt 0 10,000 0
Repayments of debt 0 10,000 0
Net cash provided by financing activities 2,883 3,562 78,518
Net increase (decrease) in cash and cash equivalents (11,395) (52,303) 63,021
Cash and cash equivalents at beginning of period 45,741 98,044 35,023
Cash and cash equivalents at end of period 34,346 45,741 98,044
Supplemental disclosure of cash flow information      
Income taxes paid 666 519 420
Interest paid 484 984 1,428
Supplemental disclosure of noncash investing and financing activities      
Conversion of convertible preferred stock warrants to common stock warrants upon IPO 0 0 611
Unpaid property and equipment purchases 205 60 312
Capital Lease Obligations Incurred 1,120    
Unpaid capitalized software development costs 0 94 439
Reclassification of the convertible preferred stock warrant liability to additional paid-in capital on the exercise of the convertible preferred stock warrants 0 0 3,202
Vesting of early exercised stock options 0 45 435
Stock-based compensation in capitalized software development $ 0 $ 257 $ 445