FYI, for a 3 month daily debit loan like this, 350% APR means paying $60,000 for a $35,000 loan. This is obviously very high, but it's not the 3.5 * the principle like many people would assume.
Also, you only double your money every 3 months if none of your loans default and you collect everything. Most of these loans default. Profits are way slimmer than you're imagining, even for the scammers (Who I definitely agree should be punished for these practices).
One insurance company had a plan with a ten-percent MLR! (Marketing plans that didn't cover anything to college kids, of course.) They took in premiums and kept ninety-percent of it as profit.