Zopa acts here as a credit agency: they evaluate the borrower's creditworthiness but the lenders keeps the credit risk. What is their incentive to do this asses

Zopa acts here as a credit agency: they evaluate the borrower's creditworthiness but the lenders keeps the credit risk. What is their incentive to do this assessment thoroughly, and how are they going to get their credibility? The idea of cutting overhead costs is good though, like you see with online banks. Credit unions (not for profit) can be another solution to avoid banks. It is very popular in Ireland for instance.