It certainly didn't help, but I think Prosper debt is pretty unwanted anyway. Even the fresher stuff.
It's plausible to me that the JDBs would rather deal with bigger numbers from places like Capital One than piddly little (and stale) sh*t from Prosper.
I don't really see this. Prosper currently has 1,179 Late-4 loans, worth $6.55M. That's an average of $5,559 per loan. And that's just the "current principal balance" -- but the JDB gets the right to the accrued but unpaid interest as well. If these loans average 6 months late and 20% interest, on average they each have about $555 of accrued interest. So each loan, on average, is worth about $6,100. That's hardly "piddly." I don't know what the average credit card balance of an account in default is, but I imagine it is of a pretty similar size.
I also don't know how long credit card companies work their collections accounts before selling them off to a JDB, but I doubt it is less than 3-4 months. So the Prosper loans probably aren't much more stale than the Capital One accounts either. While Capital One no doubt sells its defaulted accounts off in larger batches than Prosper, who cares? How is a JDB going to work 10,000 (or 50,000) accounts (from Cap One) any differently than 1,000 accounts (from Prosper)?