philanthropy has a demand side problem
Kiva and DonorsChose show that the future challenge in philanthropy will be finding and vetting recipients and then measuring the impact of a gift. Kiva has an advantage because measuring success is easy. If the loan got paid back it was a success. It may not have made a huge difference in the borrowers life but they saw a reason to take the loan, and were able to pay it back. Donors choose has a more difficult problem. When you donate there you get a nice package from the recipient showing the class room and how it is used but there is no way to tell if students learned more.
DonorsChoose might be able to use a trick from the microlending world. Teachers within a school could be a circle of trust that could help vet projects and monitor results.