Is the overwhelming use of these ~10 USD loans gambling/trading? I can't see how anyone can otherwise turn a profit so quickly. If so, can we logically conclude that most of these loans will default and that the OP is just really really generous/naive? 
I realize most of these are for gambling and i've acknowledged this earlier in the thread. I only loan to those with good reputation, so the risk is minimal. Most of the borrowers don't want to ruin their reputation over a few dollars, so they'd find another way to short the loan repayment in the event they lost while gambling. Sometimes I am willing to take a risk, but it's never more than I can afford to lose.
I see. Sorry for calling you out. I was just initially confused why anyone would partake in something so risky, but your explanation makes sense.