Credit union marketers may soon have a widening fee gap to exploit between their credit cards and those issued by banks.

Robert Hammer, card industry analyst and founder of the Card Knowledge Factory, predicted that the overall package of card fees that bank card issuers use will start to rise again after having dropped steadily for the overall industry from $23.9 billion in 2009 to $17.8 billion in 2012.

"Year-over-year growth of penalty fees hit a wall three years ago," Hammer said,  However, [w]e know of no card issuer not presently weighing its fee pricing options, or implementing higher/new fees, where permissible; by how much and how soon, of course, varies widely by issuer and their respective strategy," he said.