There's a good point made in the comments in that article (MRL) - how do we know how much flattr take as their cut?
The answer is made in their terms:
"Revenue to Site Owners: Site Owners receive 90% of the contributed revenue (monies contributed by Flattr Users and distributed to the Flattr accounts of Site Owners). Flattr retains the remaining 10% as its fee. "
I think that's just about reasonable. Certainly any more than that and I'd feel it was a little unjust.
The answer is made in their terms:
"Revenue to Site Owners: Site Owners receive 90% of the contributed revenue (monies contributed by Flattr Users and distributed to the Flattr accounts of Site Owners). Flattr retains the remaining 10% as its fee. "
I think that's just about reasonable. Certainly any more than that and I'd feel it was a little unjust.