That's a pretty standard CC fee which would be part of any flattr-like service as well. Somebody has to pay it. That's also why my ideal number was as low as 5%

That's a pretty standard CC fee which would be part of any flattr-like service as well. Somebody has to pay it. That's also why my ideal number was as low as 5%. If you have 3% or so coming out for the financial system you are then aggregating all of the stats to keep tabs on how is getting what at a very small transaction level. There is a lot of data to keep for the monthly roll-up. 2% would be a ridiculously cheap amount to take. Flattr is only keeping about 7% now, but their reporting is much simpler since they are not transacting on every impression and also because very few sites are using flattr.