Evan Schuman's StorefrontBacktalk

But what if Visa actually follows through to the logical conclusion of its card-provisioning service? Once the card numbers and passcode are stored inside the Secure Element, it has essentially become a contactless card—just without the plastic rectangle. Add a simple API that lets an app tell the Secure Element how to choose a card and spit out the encrypted account number at a POS (after the passcode is keyed in, of course), and suddenly the need for that web of agreements goes away.

Wal-Mart could do its own app that doubles as a loyalty card and Wal-Mart-specific coupon pouch. The loyalty card number wouldn’t need to be cached in the passcode-protected Secure Element, and the retailer could add whatever CRM features it liked. The right type of RFID tag at the Wal-Mart POS might even automatically trigger the Wal-Mart app, which would then feed a payment-card number to the POS.

Macy’s could do the same thing with its own app, loyalty program and coupons. Likewise Nordstrom, Home Depot, Staples, Sears and Gap. E-tailers could do the same thing, sending the encrypted card number to the Web site instead of a POS. And if a customer didn’t have the appropriate retailer’s app, a generic payment-card app—a sort of minimal mobile wallet—could be used to beam a card number to any contactless POS.

That’s not nearly as tidy on the surface as that complex web of agreements carefully managed by a mobile wallet vendor. Then again, an unbundled wallet would cut red tape and pretty much eliminate the “sorry, that retailer isn’t participating” problem that’s likely to become a lot more common as the Google and ISIS wallets start seriously fighting the wall of apathy that has stopped contactless, Chip-and-PIN and other replacements for magstripe plastic cards in the past.

And because big retailers all have their own smartphone apps anyway, cutting out the middleman and adding POS capability to the app is likely to sound more appealing to upper management than negotiating an agreement with a wallet vendor and announcing “we’re outsourcing mobile CRM to Google and the phone companies.”

That still leaves room for wallets from Google and ISIS, though not much room under their current business models. They can both still offer up coupons, for example, and maybe grab the generic payment-card functionality. But a wallet within the phone? That could be gone, replaced by the phone as a (inevitably messy) wallet.

Of course, there’s no guarantee that Visa will actually follow this through to its logical conclusion. Visa still has to cut deals with banks (a no-brainer), other card brands (if they can all play together with processors, they can do this) and mobile operators (only necessary because Visa expects to use the NFC Secure Element that’s located on a phone’s SIM).

But if Visa does close the loop, retailers might soon have a real reason to be seriously interested in getting customers to actually use this stuff.