If/How much should be given to charity?

Should we give part of the profit to charity?

How much?

Which charity?

EDIT: It looks like we are going with 65% to devs, 15% to charity and 20% to administration. Which charity?

EDIT2: To clarify, no one in the administration will profit. Any money that goes unused by hosting/marketing/advertising in the 20% will be split between devs and charity. The most likely scenario is that around 5-10% goes to administration, the 20% is just a safeguard.