Meijer Supercenters, a family-owned retail chain based in Michigan, took that approach and has seen its own increase—in sales. The efforts also led to a commendation from the Attorney General of Indiana, as well as an award for "Best Use of Mobile Marketing—Relationship Building," given by the Mobile Marketing Association (MMA).

Meijer teamed with SmartReply, a voice and mobile messaging company, to create an opt-in program alerting customers to rising gas prices. Meijer piloted the gas program at nine stores in the Indianapolis market. Customers could sign up online or by phone, or text message to receive alerts to their cell phone two to four hours before gas prices at Meijer stations were scheduled to rise at least five cents. The program is part of Meijer's ongoing efforts to reach out to its customers in ways other retailers don't.

"The Meijer campaign was the best example of how CRM programs in mobile can really drive value to a customer and drive back core potential ROI to a brand," says John Hadl, strategic advisor to Proctor & Gamble for mobile, and one of the judges for the MMA who chose to honor the program.

Meijer promoted the program through radio ads, stickers on gas pumps, and by invitations to join printed on the back of the sales receipts. The company launched the program in May 2006; gas prices then peaked over the summer. During that time Meijer sent out at least one alert a week warning of price increases to the 1,500 or so customers who opted-in at each location.

Although there isn't enough data to tell what percentage of sales have increased as a direct result of the gas alerts, Meijer has called the program a success. "The original intent wasn't to make money," says Mike Romano, executive vice president of business and sales development for SmartReply. "But if you track the people who use the program, they buy gas more often now and are more loyal customers to the store."

Meijer plans to continue rolling out the program state-by-state until the campaign is in all 176 stores sometime later this year. The company is also in talks with SmartReply to use mobile in other ways, like alerting customers to weekly sales or starting a wine club.