Consolidated Statements of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 3,898,519	$ 6,897,203
Reconciliation of net income to net cash provided by (used in) operating activities:
Depreciation and amortization	213,761	191,821
Change in fair value of stock warrants	(50,026)	(6,465,067)
Provision for sales returns	(26,120)	(100,000)
Write-off of inventories		758,638
Stock-based compensation expense	273,040	487,981
Gain on short-term investments	(16,997)
Loss on disposal of fixed assets	36,900	6,225
Changes in operating assets and liabilities:
Accounts receivable	(2,515,265)	314,163
Due from related party	1,352,918	(562,922)
Inventories	42,918	(1,364,566)
Prepaid expenses and other current assets	304,543	(322,089)
Other non-current assets	(114,618)	425,411
Accounts payable	368,479	(883,452)
Accrued expenses	(684,596)	(657,988)
Deferred revenue	(96,026)	(69,027)
Net cash provided by (used in) operating activities	2,987,430	(1,343,669)
Cash flows from investing activities:
Purchase of property and equipment	(110,583)	(1,044,871)
Proceeds from the sale of short-term investments	15,353,744
Net cash provided by (used in) investing activities	15,243,161	(1,044,871)
Cash flows from financing activities:
Dividends paid	(13,750)	(15,000)
Net cash used in financing activities	(13,750)	(15,000)
Effect of exchange rate changes on cash and cash equivalents	(128)	6,195
Net increase (decrease) in cash and cash equivalents	18,216,713	(2,397,345)
Cash and cash equivalents, beginning of period	13,204,067	10,114,163
Cash and cash equivalents, end of period	31,420,780	7,716,818
Supplemental cash flow information
Cash paid for income taxes	2,876	37,156
Supplemental noncash financing activities
Purchase of treasury stock	$ 31,456