Long gone are the days when competitive interest rates or fun card designs were enough to win "most-favored card" status among members. Today, in order to keep and optimize members' card relationships – and the interchange that comes with them – credit union issuers have to do more to make their cards "top of wallet."

But dramatic shifts in consumer shopping habits have moved the goalposts. Top of wallet used to refer solely to the physical location of a member's favorite plastic card in his or her actual, tangible wallet – now the term is also about whether members are linking their cards to their Amazon accounts, Starbucks cards, mobile wallets, and the myriad of other merchant and service provider accounts people now use to make purchases every day.

There are still ways credit union card issuers can claw their way to top-of-wallet status, though. Here are six tactics that industry experts said can help credit unions stand on the summit of today's thoroughly modern wallets.