Last Saturday was Bank Transfer Day - a date set by a number of consumer advocates and credit union supporters for the purpose of driving consumers to small, local financial institutions and raising awareness of big bank injustices. While the day was successful in spurring business for credit unions, big banks may actually end up benefiting from a mass departure of customer accounts. This is because a large swath of these at-risk accounts, by virtue of their relatively small size, contribute little to no profit for the company. What's more, big banks have been under greater financial pressure in recent months due to fiscal uncertainty in Europe, mounting overhead costs and reduced revenue stemming from new regulations such as the cap on debit card transaction fees. These financial liabilities are exasperated by these small accounts that yield minimal returns. "People are going to be moving to credit unions, and that's good for them because they're going to have lower fees, they're going to have better service, they're going to have the feeling that they are investing in their community," Motley Fool columnist Morgan Housel told DCDecoder. "And then the banks are going to be better off because they are getting rid of their least-profitable or not profitable clients."