The easiest explanation is that BoA is just trying to get rid of customers who don’t make them any money, usually by carrying extremely low balances or no balance at all. But the anecdotal evidence suggests otherwise:
Michael Jordan, 25, a software developer who lives in Higganum, Conn., says he received a letter from Bank of America in late January advising him that his card rate would rise from 9.99% to 24.99%. The software developer, who earns $80,000 per year, says he was "shocked" because his payments had been on time and his credit score hadn’t changed in the last year. In fact, Jordan says, he has only $4,500 in overall outstanding credit-card debt on two cards and that, on the Bank of America card in question, he had paid down his balance to $3,000 from $3,700 last August.
Some analysts think the bank might simply be trying to shore up profits in anticipation of dealing with the "profit sinkhole" that is Countrywide Financial and the anticipated rise in charge-offs and write-downs as the economy continues to falter. "Boosting rates on existing credit-card holders is one of the quickest levers a bank can pull to try to boost earnings," says one analyst.
"A Credit Card You Want to Toss" [BusinessWeek]