The scam is that first they tell you that you need to take on debt to "boost your credit score" and then they screw you over with insane interest rates. And just like that you are trapped in debt for a long time. Totally corrupt system and the idea of a credit score has evolved from risk management for the banks to a trap to ensure young adults all are forced to get credit cards or otherwise take out loans. Kind of like the cigarette companies trying to lure young kids in order to addict lifelong customers.