During the days when the federal bank interest rates were at its lowest, back in 2002 and 2003 to be specific, countless credit card providers offered 0% APR credit cards to many consumers. Needing only to pay the outstanding balance, smart consumers were able to charge up to their limits without incurring monthly interest charges. The question that some people were asking when these cards were at their peak of popularity was this: how do credit card providers make money off of this type of  ..