Accrued expenses (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accrued expenses
Gift card liabilities	$ 1,150,096	$ 778,237
Professional fees	322,547	1,095,526
Bonus	419,205	852,274
Deferred revenue	549,390	292,001
Other	2,591,382	2,280,751
Total accrued expenses	5,032,620	5,298,789
Non-current portion of deferred revenue	$ 900,000	$ 0
Maximum percentage of total current liabilities	5.00%