“There is the expense side of kind of building out technology and kind of framing that so that it works within the payment system,” Preston Packer, sales and marketing director for the Sandy, Utah-based core software provider FLEX, said. “Then, even though you are there, that is not a silver bullet – because then you have to drive adoption.”

Proprietary apps may give credit unions more control over card relationships with users and encourage more frequent use of credit union cards. But it's not easy, Packer noted.

“Even the largest credit unions out there – what, are they going to impress upon in their members' minds that their technology is in some way superior to what Apple or Samsung has built into a device?” he asked.

Members will also use the cards that benefit them the most – no matter where those cards sit in a mobile wallet – Packer cautioned.

“If credit unions are worried about their card being used or card adoption, they might want to review their incentive programs before they are concerned about building a mobile wallet,” he said.

Working within the confines of platforms owned by Apple, Samsung, Chase and a mushrooming number of retailers appears to be a natural response to the expense and adoption questions, and it gives credit unions something to present to members right away. But that route comes with its own set of challenges: It often means giving away interchange revenue and valuable data, as well as constantly having to remind members to use certain cards.

Those challenges are big reasons why people such as Annette Zimmerman, president/CEO for the Houston, Texas-based PrimeWay Federal Credit Union and CU Wallet board member, prefer the proprietary route over the long term. PrimeWay has $464 million in assets and 48,000 members.

“The consumer is not going to want 20-plus separate apps,” she said. Members would rather have mobile wallets from their financial institutions, she explained.

Zimmerman said she believes members will remain loyal to perhaps five to seven retailer-branded payment apps, but institution-branded mobile wallets that tie into merchant reward programs and merchant coupons are very attractive. Adding features such as cardless ATM access gives members another reason to use a credit union's app and helps form a habit of repeated use, she added.

Some research appears to support those arguments. More than half (55%) of interested non-mobile wallet owners in a recent survey by consulting firm First Annapolis of 1,528 smartphone users, for example, said they would prefer an offering from their own financial institutions; 40% of current mobile wallet owners said the same. Only 20% or fewer of current mobile wallet owners said they'd prefer an Apple, PayPal or card brand offering.

Mobile commerce consultant Richard Crone has another take on the theirs-or-ours argument: Do both. Only supporting the Apple Pays of the world isn't a strategy, he said; credit unions should also invest in their own offerings.

“It's not an either or. This is a multi-front war,” he said. “Credit unions need to fight for enrollment using their own branded app – and make sure their cards are linked inside these other embedded payment experiences.”

Beyond the proprietary and third-party choices, there is a fourth option: Doing nothing and waiting to see how things shake out. But that risks alienating tech-savvy members who will look elsewhere, Crone said. In other words, the objective is to avoid a loss rather than score a win.

“If they give up this touch point, they will give up the opportunity to serve the member in context, in the wild, where it means something,” he said.

Besides, credit unions looking for measurable returns on mobile wallets are missing the point, according to a recent report by mobile financial services industry association Mobey Forum.

“There is no ROI,” the report said. “While mobile payments may not generate a financial return for banks and may indeed prove a net cost, they will play a valuable role as a loss leader, reinforcing the bank brand and the bank's control of the customer relationship and opening up the door to selling other more valuable services.”

“The safe bet is always going to be on your brand with your accounts in your app,” Crone said. “When you delegate that to others, it's really more of a defensive strategy.”

That may not be a good enough reason to run head-first into mobile payments, though. Packer said a credit union should at least have a mobile banking app first, before venturing into mobile wallets. Plus, mobile banking apps can accommodate other lucrative, growing products such as mobile lending, institutional transfers or peer-to-peer transfers, he noted.

But whatever the path, just watch the clock.

“Right now, more than half of the millennials say they will switch financial institutions for the mobile payment capability at the physical point of sale,” Crone said. “So hold onto your horses, man.”