Dr. John Stanton, a St. Joseph's University professor of food marketing, smiled and thanked the grocery store cashier who rang up his gallon of milk. She sullenly ignored him.

"Some people say you're welcome," Stanton said as he took his purchase.

The cashier glanced up just long enough to reply, "It's printed on the receipt."

Stanton ended his "horror story" with a laugh. "I wish they had self-checkouts at all those [kinds of] stores."

The self-checkout machines at your local grocery store might disappear, according to the trends of a report released earlier this year by the Arlington, Va.-based Food Marketing Institute (FMI). The Food Retailing Industry Speaks 2011 cites market trends showing that self-checkout use declined noticeably in 2010. According to the report, an average 15.8 percent of customers used self-checkout lanes at grocery stores that offered them. This is the lowest percentage since 2006.

Supermarket chain Big Y announced this month that it will be removing self-checkout machines in its stores. Albertsons also will be removing its machines, and Kroger is experimenting with cashier-staffed quick checkouts at a new Texas store. Other supermarkets, however, are content with their current situation.

"I really don't see them leaving…even though we have a lot of trouble with them sometimes," said Monica Mazzini, manager of the Purcellville, Va. Giant. In spite of a "bossy" operating system and problems accepting coupons, Mazzini reports that 30 percent of customers use her self-checkout machines every month. Mazzini likes and uses self-checkouts herself, preferring to "do things my own way."

Carolyn Evertz, an administrator for FMI, also has confidence in the future of self-checkout machines. "There is no industry-wide removal of self-checkouts," she said. "It's really a customer service decision."

Many factors contribute to a store's deciding to remove self-checkout machines. The Food Retailing Industry Speaks, referring to a survey conducted by The Retail Feedback Group, writes that customers report greater satisfaction when they use a cashier-assisted checkout. Machine glitches and customer theft, as well as cashier training and employment, also play into the decision.

"I hate them," said Betsy, a Giant cashier. "They're terrible because they take away my job." Betsy routinely monitors the self-checkouts at her store and knows firsthand about the large amount of trouble the machines can cause. "I use them myself, but I don't like them as a cashier."

Kim Prack, a customer in Betsy's line, piled mounds of Halloween candy and cans of green beans onto the conveyor belt. She does not mind using the self-checkout, but today she braved the long lines to have a cashier help her. "[The self-checkout] is for people who seem to have fewer items."

Stanton said that customer service determines in great part consumer reaction to self-checkouts. Cashiers, least of any grocery store employee, receive the fewest hours of training. Those stores that do train their clerks want to get a return on their time investment instead of replacing cashiers with machines.

"This will be a moot question in a few years," Stanton said in conclusion. "The really exciting technology is the RFID."

RFIDs, microscopic chips that can be embedded in ink and read by scanners, might dominate grocery store technology in the next five to seven years. Customers can simply roll their cart through a specialized detector that will read the RFID chips on items in the cart. Then, the detector can automatically tell customers how much they must pay. "You'll no longer need a checkout," Stanton said.

Even now the technology is used in grocery store warehouses. When delivery trucks bring shipments of food to your local store, managers use RFID chips to inventory the items they receive. "The only thing is the cost of putting these chips in every single item," Stanton said. RFID chips must drop from six cents to one cent a piece to become viable.

Until then, we'll have to stick with cashiers and self-checkouts. "It's not quite as simple as driving over the bridge and using your EZ Pass," said Stanton. At least, not yet.