While you or I wouldn't look twice at this people who have had some medical expenses, or had their hours reduced at work, or simply don't understand how interest works against them (which appears to be a significant number of people) will take them up on that offer. I don't know where you live, but they know that mailing those into areas of households where the average income is less than $40,000/yr will get them a huge return, even when some default.
Why is this even legal? - Because enough of us won't educate ourselves and get off our collective asses and stop it. I am astounded that we as a people are letting that industry lobby against us, put their own people in government positions to influence policy, and take so much money out of the pockets of working people. It's not an easy subject, and how to put it in sound-bite form is a challenge, but we are on the hook for trillions because the banks and their friends in the government are spending all their time figuring out ways to take taxpayer money, while the taxpayers are busy at work and home.
And even when we elect people that should be on our side, who benefits from the outcome is certainly questionable. Despite the salvation of the banks in 1929 we still entered the Great Depression and that provided the impetus to reform banks. By using taxpayer money from 2008 to now our government has prevented real reform (the FinReg legislation notwithstanding) that could have provided much more protection from an almost certain future financial crisis. Barack Obama made a speech to the bankers in March of 2009 - he told bankers in a meeting that his administration was "the only thing between the bankers and the people with pitchforks",
here... and here.... Why in the hell he decided he should protect the wealthy by encouraging the use of the taxed wages of working people to repay the "bets" made by those with more money than they could ever likely spend, both in this country and overseas, while 30 million Americans became unemployed or underemployed I will never understand.
Just FYI, there is a book out there called Broke, Inc, which details a history of, mostly, the payday loan business. Very enlightening. Very interesting read on how payday lenders are able to charge a 400% APR on payday loans, an extremely lucrative business. It also touches on the instant loans made by tax prep places. There is a huge industry dedicated to taking money from those with the least. One stat from the book shows that people with incomes of less than $20,000/yr pay an extra $900 in various fees that are not charged to people with greater incomes, all the way from debit card issues through payday loans and check cashing.