Given that many charities that pay up to 95% of the funds they raise to third party marketing companies, I don't think it would be out of line at all to give th

Given that many charities that pay up to 95% of the funds they raise to third party marketing companies, I don't think it would be out of line at all to give the sites hosting these ads a cut of the funds they raise. There's nothing wrong with offering a win-win proposition, and it would get you more traction.