Despite its influence in the smartphone realm, Apple is only one part of a complex world of wireless financial transactions that involves banks, credit card processors, smartphones on several operating systems, merchants and NFC payment terminals, analysts said.

In the U.S., which lags behind Japan and South Korea on contactless payments, there is already a well-established banking network that supports customers with credit cards and ATM machines to provide a ready supply of cash and credit. Such a variety of choices for buying things has reduced the demand in the U.S. for phones with NFC technology for making mobile payments. Recent polls show that Americans aren't that interested in using NFC smartphones or mobile payments. (Mobile payments is a broad category that includes using text messaging, contactless payments and the Web to make payments and purchases from a mobile device.)

"To date, mpayments [mobile payments] in the U.S. have seen minimal growth, despite high estimates over the past decade," market research firm IDC wrote in a May report. "The U.S. consumer is not yet sold on mpayments, as only 19.3% have decided to make a payment using a mobile device." That 19.3% represents 494 respondents out of 2,560 people surveyed, IDC said. Of that 494, only 7.7% (38 people) had used a mobile device with NFC.

Apple has long been expected to launch the next iPhone, possibly by this fall, with an NFC chip inside that would work with some type of mobile wallet app to allow quick purchases from merchants or transit providers. Users would enable the app, probably with a PIN, and quickly pass the phone near a payment terminal to transfer funds from an established account, likely a traditional credit card, such as Visa, MasterCard or American Express.

Google launched Google Wallet for NFC-ready Android phones on Sprint last September, and despite more than 100,000 payment terminals in the U.S., the project has thus far seen only modest success, analysts noted.