Some stats from the last few months: started on Lending Club in October 2013. Now up to 152 notes in various stages of maturity – overall, of course still kind of early: the oldest notes I have are only 8 months old. So far the Adjusted Net Annualized Return is steadily over 20%, the current number is 20.52%. Very few notes are late. Of course, I expect late and charge-off rates to increase as the notes mature, but so far it’s surprisingly steady, knock on wood.
The biggest catch: this is not very liquid at all. If a decent APY holds, you get your money back in a few years, there is no practical way to just get out. There is a trading platform where you can in theory dump the notes in case you need your money back, but I haven’t tried it.