Debit card merchant fees are already significantly less than credit card fees and will almost certainly fall even lower under Dodd-Frank. And if, under pressure from the DOJ and private plaintiffs, card issuers let merchants offer discounts or surcharges that encourage customers to use their lowest-fee cards, consumers could decide en masse to use debit cards to save a few cents at the register. This could mean the end to popular rewards programs offered by the card companies, but would also likely save retailers and merchants billions of dollars.
Will New Debit Card Fee Controls Revolutionize Card Industry? – The Center for Public Integrity