It's not a zero-interest loan, but the Kiva "field partner" pockets the interest, so there's no possibility of return. From their website:
"Lending to the working poor through Kiva involves risk of principal loss.
Kiva does not guarantee repayment nor do we offer a financial return on your loan. "
What are the regulatory obstacles to running a business that does offer a small return? I have to assume there are some, no, or else you get loan sharks.
"Lending to the working poor through Kiva involves risk of principal loss. Kiva does not guarantee repayment nor do we offer a financial return on your loan. "