Are Wal-Mart's New Checking Accounts a Game Changer?

More than a quarter of Americans are unbanked or underbanked, according to the Federal Deposit Insurance Corporation. Without access to traditional banking services, many pay thousands of dollars in fees to use check-cashing services, payday loans and other alternative financial services. New players like mobile banking startups and potentially even the U.S. Postal Service hope to fill the gap left between traditional bank services and their alternatives.