That's an interesting idea. Currently there is no financial incentive to pick successful projects, because the entrepreneurs don't receive the repayments personally. We may add something like this in the future.

From my experience, most people in developing country communities such as our entrepreneurs' routinely act altruistically and give away a much higher percentage of their resources than in industrialized societies.

As a former economics student, I've been constantly surprised by the extent to which simple altruism motivates behavior at Zidisha. The original Zidisha concept was a marketplace based on financial incentives (including interest for the lenders), but most of our users didn't want that.