I've been using contact-less payment methods for about 7 years. The only problem is that I did not start using them in the U.S. Sony had come up with the Edy Card a while back and it is a prepaid NFC card, like a credit card. Soon thereafter, a lot of mobile phones incorporated the Edy technology as more and more things used the technology. Our company's building was run on the Edy technology for entrance into our building. Check also on Pasmo and Suica in Japan. Vending machines in Japan have either Edy or Suica, and you can use your phone.
So, will it save retail? I doubt it. Why? Because this technology has been around for a long time (in tech terms). It was available even before the iPhone and Android phones. It didn't matter. Finally I see signs in chipped credit cards, but it also has been around for a long time. Mobile phone makers aren't putting them in phones that are marketed in the U.S. Checking on how Japan uses the NFC technology, it doesn't change retail spending habits. You still need the money (in pre-paid Edy and Pasmo - Suica is backed by a charge card) and a lot of people in Japan are credit adverse and most cards are charge cards not credit cards. Thus, in a country that is supposed to have a lot of money, it isn't helping.