I'm not sure how it is in the US, but in Australia, the small loan industry (payday loans or advances, as we call them here) is regulated by things like an annual 48.5% cap on interest rates on loans in New South Wales and similar regulations in other states. One of the issues, however, is that some loan providers are quite crafty and come up with creative ways to achieve up to 500% p.a. by cycling through loans and deeming advances to be separate and not one single loan. Clever use of defining what is a loan fee, what is interest, what is an account fee and that kind of thing. Things that are not in the spirit of the legislation.
So, for those clients irresponsible enough to take out multiple 'advances' over the course of a year, the fees stack up each time. For instance, a client might borrow $500 and be required to pay back that initial advance plus $100 over three 'weekly' pay cycles. Yes, our pay cycles are quite flexible. Most are weekly or fortnightly. Well, if they were to do this once every 3 weeks (17x a year), that would amount to $1,700 in interest and fees on a recycled $500 loan, which is a cumulative 340% p.a. Plus the usual account fees, late fees, associated charges etc. There's not many places you can get that kind of ROI elsewhere.
But consumers are not that dumb, surely? Well, yes they are. I've seen it first-hand and I stay well away from the whole industry.
Definitely not enough consumer awareness in this area.