Interest rates can vary considerably from card to card, and the interest rate on a particular card may leapfrog dramatically if the card user is last-minute with a payment on that card or any other praise instrument, or even if the issuing bank decides to raise its revenue. As the rates and terms vary, welfare work have been set up allowing users to calculate savings on hand by switching cards, which can be considerable if there is a doozer outstanding equanimity (see Free Credit Report external links for some on-line services).

Director Kevin Smith funded Clerks. in cut by maxing out disparate glory cards. Richard Hatch also financed his production of Battlestar Galactica: The Second Coming partly through his reliance cards. Famed hedge fund officer Bruce Kovner began his career (and, later on, his firm Caxton Associates) in financial markets by borrowing from his fame card.