Mixing it up
In theory, high-speed computing and data crunching allow retailers to counterpunch a competitor's prices on a daily or even hourly basis. In reality, most supermarkets remain slaves to the ingrained weekly cycle of their advertising and vendor deliveries.
That said, retailers mix up marketing today as never before, making it more difficult for consumers to dial into a store's sales rhythm. Even Walmart, the nation's largest food retailer by far, offers three pricing tiers: EDLP, "rollback" and "save even more," which is essentially a sale.
"It's become extremely dynamic now," Stern says. "You've got this gigantic competitor that has forced its competitors to get a lot smarter and more sophisticated about what they're doing."
With margins already wafer thin and everyone from Target to Ikea invading the food space, grocery chains are doubling down on loyalty programs and mobile technology to attract and retain customers.
In the near future -- given your consent, of course -- that same loyalty program will know when you enter the store by the GPS on your mobile phone, and use it to guide you aisle by aisle to advertised and unadvertised savings based on your shopping history.
"They are trying to see how to best customize their value to you," Shankar says. "Once you learn their pricing strategies, you just experiment to determine their value proposition to you."