Visa's V.Me system, , also spans online, mobile and in-store purchases, but Visa is holding that offering closer to its chest than MasterCard is, Hung said. That should mean consumers are offered more opportunities to sign up for PayPass Wallet, he said. And compared with PayPal, which is approaching the in-store space from online and mobile by slowly building up a network of point-of-sale devices, MasterCard has a head start in the hardest part of the equation, he said.

MasterCard won't get paid when consumers use a rebranded PayPass Wallet-based service and choose another brand of card, but offering the service does give MasterCard some advantages, said Geoff Iddison, group executive for innovative platforms at the company's E/M-Commerce division. For example, banks that use the platform could offer MasterCard customers sign-ups for PayPass Wallet before users of other cards, he said. Iddison expects the wallet to be used with MasterCard cards 80 percent of the time.

The built-in PayPass radios in ultrabooks are designed to let consumers make online purchases using physical credit cards for extra security. Intel is building support for the PayPass components into its chips for ultrabooks and has built reference designs of systems with the radios built in. Manufacturers will be able to start offering ultrabooks with PayPass built in starting in the second half of this year, said Amit Bodas, a strategic planning manager at Intel.

PayPass tapping will work in conjunction with the identity protection technology built in to all ultrabook platforms. The combination of the consumer's own card tapping their own ultrabook, in conjunction with using PayPass Wallet on an online store, will provide multiple factors of authentication, Bodas said.

Gartner's Hung thinks digital wallet adoption has been constrained by the weak economy but will show significant growth over the next few years. Yet he cautioned that traditional credit-card purchases will still far outnumber digital wallet purchases in five years.