|
Summary of significant accounting policies (Details 6) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2012
|
Jun. 30, 2012
|
Mar. 31, 2012
|
Dec. 31, 2011
|
Sep. 30, 2011
|
Jun. 30, 2011
|
Mar. 31, 2011
|
Dec. 31, 2012
item
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Segment and geographical information | |||||||||||
| Number of reportable segments | 1 | ||||||||||
| Revenue | $ 28,000 | $ 26,017 | $ 24,302 | $ 24,187 | $ 25,899 | $ 24,688 | $ 22,943 | $ 21,028 | $ 102,506 | $ 94,558 | $ 80,420 |
|
Retail subscription
|
|||||||||||
| Segment and geographical information | |||||||||||
| Revenue | 32,716 | 29,033 | 23,561 | ||||||||
|
Retail single-use
|
|||||||||||
| Segment and geographical information | |||||||||||
| Revenue | 13,429 | 16,054 | 17,460 | ||||||||
|
Wholesale
|
|||||||||||
| Segment and geographical information | |||||||||||
| Revenue | 49,495 | 43,707 | 35,134 | ||||||||
|
Advertising and other
|
|||||||||||
| Segment and geographical information | |||||||||||
| Revenue | $ 6,866 | $ 5,764 | $ 4,265 | ||||||||