Since I pay my balances in full every month I'm not sure. But, it's in the plans of most major credit card banks to do so in the not so distant future.
Its 4% for credit cards and its basically a way to "help people help themselves" paying the minimum with your cards makes you a slave of the credit card companies for many many years. Now mizer stop being cheap and payoff your bill. You're a big time trader arent you? Ill give you $40 for your ebay item....