Credit card companies charge merchants -- . And that is passed on to the consumer. There's no way the transaction costs the big banks 3%, it's a cash cow for them, and their profits are at an all time high while main street is still in recession.
The free market doesn't limit the fees because the fees are passed on to all consumers, not just the ones that use cards with particularly high fees.
It's time to limit credit card merchant fees. Perhaps a reasonable cap would be 0.5%.