[zu03776]

So instead of losing 2.9% + 0.35 on donor and 5% on recipient, why not lose 16.5% instead? #winning

From the FAQ at https://flattr.com/faq#23 :

We take 7.5% of received revenues (to keep Flattr running, develop further and handle chargebacks and fraud). Our payment provider (MangoPay) charges 9% of received revenues (please see this blog post for more information). These fees are withdrawn on the 1st of the month for revenue received in the prior month.

Whenever money is withdrawn (currently the minimum amount that can be withdrawn is $10) a $3 fee is charged.