[syntheticzero]

I don't know what you mean to imply with this question ---- when you donate to any non-profit, the money might be spent on any number of things, including overhead, as well as money sent on to beneficiaries. The only difference with DonorsChoose is that we actually give donors a say in how we spend their donation: on overhead, on materials sent to a specific classroom, or a combination. (Donors can decide to send a donation specifically to cover DonorsChoose overhead, in which case all the money goes into our general fund). The donor may also decide to donate to more than one proposal --- it could be two or three or five or ten proposals at once. That is also one credit card charge.

I really don't see why you assume that because the money being donated is spent on multiple things that would be separate credit card charges. That makes no sense, who does that? I can't think of any e-commerce site either in the commercial or non-profit space that would do this for no apparent reason.

I might add that, though I think this is more or less irrelevant, DonorsChoose does not send the money directly to teachers, but instead purchases the materials itself and has them shipped to the teachers (this is to reduce the incidence of fraud, and to make sure the money is spent on the materials the teacher said they would spend the money on --- the specific materials are chosen by the teacher, but we actually do the purchasing). If a donor specified all their donation go to the teacher and students, then the money they donate goes only to the vendor(s) for that proposal, who then ship goods to the teacher at their school, and the money we spend on staff expenses, web hosting, etc., etc. has to come from donations earmarked for overhead (including the optional donations).