Decent and profitable: tier the fee ($.05/$1, $.10/$2, etc.)
Required for not being a dick: whatever the donation level says is what the donor pays. Doesn't matter whether you price it at $5.40 or take $.40 out of a $5 donation, it is misleading business practice to show a lower price but charge a higher one, which has gotten people sued.
Re: Alas!
Nice: waive the fee on $1 donations.
Decent and profitable: tier the fee ($.05/$1, $.10/$2, etc.)
Required for not being a dick: whatever the donation level says is what the donor pays. Doesn't matter whether you price it at $5.40 or take $.40 out of a $5 donation, it is misleading business practice to show a lower price but charge a higher one, which has gotten people sued.