Let's not dismiss the wireless carriers as potentially potent players in mobile payments.

Isis -- the mobile commerce venture backed by AT&T (NYSE:T), Verizon (NYSE:VZ), and T-Mobile (NASDAQ:TMUS) -- is hoping that giving away 1 million Jamba Juice smoothies will help kick off the launch of the Isis Mobile Wallet later this year.

Jamba Juice parent Jamba (NASDAQ:JMBA) has been open to mobile payments in the past, and this move makes sense. We don't know the exact terms of who will cover the tab for the million blended fruit beverages "purchased" by customers using the Isis Mobile Wallet, but it comes at an ideal time for Jamba. Company stock tumbled like berries into a blender earlier this month after Jamba hosed down its sales guidance for the balance of the year. This high-profile promotional stunt may introduce new customers to Jamba Juice, and that could be a game-changing experience to folks who are used to choosing between the only two to three boost-less smoothies available at fast-food chains and coffee shops. 

However, this could also work well for AT&T, Verizon, and T-Mobile. Why should PayPal, Square, and other buzz-worthy mobile payment platforms get all of the glory here? The three carriers set their competitive differences aside to create Isis, and the rollout of Isis Mobile Wallet should be the crowning achievement for the three companies.

It may not be an easy sell. For starters, Isis Mobile Wallet is limited to NFC-enabled smartphones. In other words, don't try this at home with your iPhone. However, it's not just about having an Android device that happens to play nice with an NFC chip to tap for purchases. The device also must have an enhanced SIM provided by AT&T, Verizon, or T-Mobile. It is only then that they can download the Isis Mobile Wallet app and then work their way up that free smoothie. 

The neat thing about the limited promotion is that we will see how successful it ultimately is in getting early adopters to embrace the carrier-backed platform. After all, this giveaway is "up to" 1 million free Jamba Juice smoothies. If enough subscribers to the three carriers don't jump through the hoops to set up the mobile wallet, Jamba will have some sad blenders lamenting the free beverages that they failed to give away.

Longtime Fool contributor Rick Munarriz owns shares of Jamba. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.