One of my Kiva loans has been completely paid off! Yay! It was one of my two Christmas present loans (I asked for Kiva gift certificates for Christmas and got two of them). It was to a group in Paraguay, because the person who gave me the gift certificate has connections to Paraguay.
For that reason, I decided to reinvest the money into another business in Paraguay, which is still trying to raise money at this time. In fact, there are a TON of businesses that need financing at the moment (about 300). So if you have a spare $25 and a few moments, there are worse things you could do than make a microloan.
And, if all goes well, you'll get your $25 back to reinvest or withdraw in just a few months. Loan defaults are rare, but happen. Most of the time you'll get the money back to pass on to someone new.