Accrued expenses (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Accrued expenses
Gift card liabilities	$ 778,237
Professional fees	1,095,526	107,134
Bonus	852,274	1,224,929
Other	2,572,752	1,150,192
Total accrued expenses	$ 5,298,789	$ 2,482,255
Maximum percentage of total current liabilities	5.00%