Who in their right mind donates for free?
If you donate for free you contribute to a higher hash rate which hurts all of us, including yourself.
What a senseless statement. You don't contribute anything and the same logic implies, incidentally, if you sell 0.05 btc coupon for 0.01 btc.
Donate means free. If if you charge money, then it is a sell. Are you planning to declare taxes on this sell?