Interesting read about how much banks have been making off of interchange fees from debit cards. According to this CNNMoney.com article
Bank of America executives said the new rule would reduce fees earned from debit cards anywhere between 60% and 80% starting in the second half of 2011. This year, the company said it expects to produce $2.9 billion in revenue from that business.
The article mentions that regional banks such as KeyBank, Regions, Fifth Third and TCF Financial will be hit even harder. In 2009, 10% of TCF's revenue came from interchange fees.