Isis, the AT&T, Verizon Wireless and T-Mobile's mobile payment venture launched at the end of last year, is still largely a concept, but it has already been scaled back from its initial grandiose vision of competing with Visa and MasterCard by letting customers maintain accounts with the wireless carriers and use their smartphone devices to make small purchases. Discover, also a partner in the group, would use its payment network to facilitate the transactions.

Transportation, for instance, was seen as the ideal venue and in fact, Isis recently inked an agreement with officials of Salt Lake City and the Utah Transit Authority to make the entire transit system mobile-fare-payment enabled. However in other significant ways the early promise of Isis is being rolled back, the Wall Street Journal now reports. The group has now set a less ambitious goal of merely storing and exchanging account information on an existing Visa or MasterCard, according to the Journal, and is in the process of discussing this model with the card companies.

One stumbling block was that retailers are more likely to accept Mastercard or Visa than Discover. These issues are already playing out in the Salt Lake City contract. "If people don't have, say, a Discover card, will they have to apply for one? That is not clear," Kolja Reiss, managing director of Mopay, told The E-Commerce Times when speaking of the Utah pilot project. "Unless Isis is based on a very broad set of credit card and banking relationships, its use will be limited."