(Source: The Baltimore Sun, Maryland)

BALTIMORE _ Faith E. Wachter doesn't normally spend as much as $17 on shampoo in a single shopping trip. But by stocking up on hair-care products recently, the Ellicott City, Md., resident saved more than $4 on gasoline for her car _ and just in time for a drive to the beach.
As they look for ways to spend less on fuel, more shoppers are headed to the supermarket.
Several chains are rewarding loyal customers with points they can redeem for discounts at the pump. And with the cost of a gallon of gas up a dollar from last summer, consumers say they are comparing the different programs _ and, in some cases, shopping accordingly.
"It's like buying a winning lottery ticket," J.D. Taylor said as he filled up at the Safeway gas station in Catonsville, Md.
"How can you lose?" the Woodlawn, Md., man asked. "The card is free."
Consumer advocates caution against the potential pitfalls of such programs. It's true, they say, that customers might save money, as long as they don't let the lure of discounts change their regular shopping habits.
But because it costs retailers money to offer and promote such discounts, they say, prices in general might be lower if they didn't exist in the first place.
"I don't think consumers benefit by encouraging these programs," said Joseph Ganem, a physicist at Loyola University Maryland who has written a book on how consumers are deceived by numbers.
"These companies are paying a lot to implement them," Ganem said. "You're paying for that."
The supermarket programs are pretty similar: For every dollar you spend, you earn a point. For every 100 points you redeem, you get a 10-cent-per-gallon break when you fill up at the pump.
As gas prices have climbed this year, so has the popularity of supermarket discount programs.
Participation in Giant Food's Gas Rewards program has increased by 5 percent in 2011, according to a spokesman.
Giant has nine stations in Maryland, Washington and Virginia, spokesman Jamie Miller said, but customers may also redeem points at participating Shell stations.
Chris Brand, a spokesman for Martin's Food Markets, speaks of the instant gratification customers experience when they swipe their bonus cards at the pump and see the per-gallon price drop.
"That's always a thrill.