Do you have consumer debt on credit cards from big banks, and want to save a few hundred dollars? Then switch to smaller banks and credit unions. A report by the Consumer Financial Protection Bureau says the 25 largest credit card companies charge about 10 percent more interest than their smaller counterparts. Mark Hamrick, a senior economic analyst at bankrate.com, tells NTD that the bigger banks do this “because they can”—aided by their brand familiarity and their promises of cashback, premiums, and perks.