CINCINNATI, OH - Kroger opened its 1,000th gas station earlier this week, a milestone that the Associated Press characterized as underscoring the "growing link between groceries and gas in the drive to build customer loyalty."

In the past five years, Kroger, the nation's largest traditional grocery chain, has nearly doubled its gas station count. Last year, it began aggressively expanding its customer rewards tie-in with Shell, a program that has grown from a pilot launch in five markets to nearly 5,000 Shell stations in 26 states.

Kroger's loyalty program rewards consumers with pump savings of 10 cents a gallon for every $100 spent on groceries.

Fuel sales now account for nearly 12 percent of Kroger's grocery revenue, and officials say that the offering helps boost its customer base.

"It's about customers shopping our stores and being loyal Kroger customers," said Chris Hjelm, a Kroger senior vice president. "More and more customers are engaging in the program."

Hjelm said Kroger intends to keep expanding its gas program, with gas rewards being tried at some of its nearly 800 convenience stores.

"Grocery really is the perfect combination," said Dan Little, Shell's North America fuels manager. "It works so well because of the frequency of purchases and the size of the spend."