Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities
Net income (loss)	$ 345	$ (1,342)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	842	309
Amortization of intangible assets	436	502
Non-cash interest income	(12)	0
Loss on disposal of property and equipment	3	0
Bad debt expense	0	43
Inventory write-down	141	18
Stock-based compensation expense	1,250	367
Non-employee stock-based compensation expense	29	11
Change in fair value of warrant liability	1,631	1,201
Change in fair value of option liability	0	437
Changes in assets and liabilities
Accounts receivable	(2,142)	(6,039)
Other assets	(591)	(184)
Inventories	290	121
Prepaid expenses and other current assets	(675)	(1,143)
Other long term assets	(871)	0
Accounts payable	(2,030)	(311)
Accrued liabilities	827	1,753
Warranty reserve	(207)	119
Other long term liabilities	0	18
Deferred revenue	2,499	2,874
Net cash provided by (used in) operating activities	1,765	(1,246)
Cash flows from investing activities
Purchase of property and equipment	(909)	(920)
Purchase of short-term investments	(59,903)	0
Net cash used in investing activities	(60,812)	(920)
Cash flows from financing activities
Borrowings	0	4,500
Principal payments on long-term borrowings	(8,333)	(571)
Proceeds from initial public offering, net of offering costs	72,221	0
Payment for repurchase of early exercised options	(6)	0
Proceeds from exercise of stock options	384	1,810
Proceeds from exercise of preferred stock warrants	0	2
Common stock issuance costs	0	(382)
Net cash provided by financing activities	64,266	5,359
Net increase in cash and cash equivalents	5,219	3,193
Cash and cash equivalents at beginning of period	14,898	8,642
Cash and cash equivalents at end of period	20,117	11,835
Supplemental disclosure of non-cash investing and financing activities
Costs related to the initial public offering in accounts payable and accrued liabilities	202	382
Property and equipment in accounts payable and accrued liabilities	$ 109	$ 450