In February, Isis, the NFC joint venture between AT&T Mobility, Verizon Wireless and T-Mobile USA, announced that Chase, Capital One and Barclaycard had signed up to offer NFC mobile payments capabilities through the group's mobile wallet service.

More recently, American Express arranged to have its payment application, Serve, integrated into Isis, which has been piloting its system in Austin and Salt Lake City since late last year.

Now Capital One has pulled out. Capital One spokesman Chris O'Neill confirmed to Mobile Payments Today that Capital One is no longer available in the Isis wallet. He declined to elaborate and said the bank "will continue to work with Isis to evaluate options for a continued presence in the Isis mobile wallet."

Joe Frisz, president of Paytroniks, believes the departure is partly a statement about NFC, which hasn't caught on in the U.S. Recent moves by PayPal and Apple to employ Bluetooth Low Energy for mobile payment systems "really change the game," he said, noting that Isis competitor Google Wallet also appears to be moving away from NFC.

"I think this is Capital One saying the results aren't what they expected and they don't want to put their eggs all in one basket," he said. "They'll let Barclays and Chase go ahead and keep experimenting with the technology, but they'll look elsewhere for a mobile payments alternative."

And there's ROI. Isis has confirmed spending $100 million on its wallet, but many industry observers put that number north of $300 million. "Capital One, I'm sure, has access to how much revenue the pilot can generate," Frisz said, "and they're not seeing a return on that investment. I don't think the numbers add up."

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