Welcome Tigerapex
Kiva currently doesn't charge interest on the money we loan. I imagine if they don't get enough funding through donations anymore, they might introduce a low interest charge to the MFIs to cover their expenses.
It's difficult to say if this would be rolled over to the MFIs' clients as they might not get special terms compared to other borrowers of that MFI. Instead, those whom we fund might not otherwise qualify for the loan... if that's the case, simply assuming the risk, as we do, would be enough to make offering that loan attractive for the MFI - even if a low interest were charged.
There was a long discussion of whether or not lenders should be paid interest. You can read about it
here. I don't think the discussion included the topic of Kiva charging interest to become self sustainable (and no longer depend on donations), but it's certainly an interesting approach.
One thing to keep in mind is that a for-profit company called myC4 does something similar: they charge a little interest that goes to them and lenders are paid about 11% interest as well. They don't seem to have a problem finding qualified entrepreneurs, but they seem to include largely borrowers who already are established (sometimes with significant revenues) and are trying to expand further. This is certainly also needed if the goal is to boost a country's economy, but the different target group might not interest Kiva lenders as much. So any interest charged would have to be low to keep the current types of entrepreneurs.
