In the late-70s and into the '80s, the store where I worked offered financing and many people used it for their purchases at a time when interest rates were very high (remember the economy when Carter was POTUS?). The bank we used offered credit cards that allowed a second line of credit for double that of the card's normal line, at 18% interest, called 'Revolving Installment Plan'. I thought the acronym 'RIP' was pretty accurate. One of the guys who worked there used his credit card to buy a new car since auto loans were higher than 18%, so he saved over 6%/year.