BTCJam is a total scam and its owners belong in jail.
You cannot come to a conclusion so quickly, dude. See this! syndria is getting repayments from time to time and he'll probably reach ROI if he receives 2 more payments.
I was wrong that should be 3 not 2. But i already received 3 times on time and the total amount loaned is 20 Bitcoins that is pretty huge and that was not his first loan so i believe he will pay the remaining debt.