The coupon has gone cellular.
Using a free service from a new company called Cellfire, shoppers can download coupon numbers onto their cellphones, show the code number to a salesclerk and get the same price break as the person clutching those ragged old paper coupons.
About two-thirds of the users of the "mobile coupons" are 18 to 34 years old, Cellfire says. That's probably because they're accepted at Papa John's Pizza, Domino's Pizza, Subway, T.G.I. Friday's and Cold Stone Creamery, and they work with Alltel, AT&T and Verizon Wireless data plans.
