LEWISTON – Barbara Everett worries that her business, Elizabeth Ann’s General Store, may have its best year ever and still close.

The reason is a razor-thin profit margin and a gamble that began on Feb. 24. For the first time since 1976, her store began accepting credit cards.

“I’m on the fence about it,” Everett said. “There is no margin anymore. And I’m giving some of that up.”

Without the change, she fears her business might close. Too many folks have grown accustomed to buying gas and convenience store munchies and beer with a credit or debit card.

“We’ve seen a steady drop in business since 2004,” she said. “We know it’s because of the cards.”

The plastic marketplace has been unkind to the store.

Barbara’s dad, Donald Everett Sr., opened the shop at Sabattus Street and East Avenue and named it after Barbara’s mom. After the first year, he discovered that half of his total income went to the banks for the credit card fees.

“If you have 500 customers a day (each creating pennies in fees), that’s a lot of money at the end of the year,” Barbara Everett said.

When her father could, he went cash only.

That worked until the past few years, when credit and debit cards became omnipresent, used for everything from breakfast cereal to Big Macs.

Cashiers grew used to dealing with customers who were angry by the store’s refusal to accept credit cards. Barbara Everett installed an ATM so people could access their bank accounts, but it did little to appease them.

Then this winter hit. The profit numbers forced Everett to re-examine the credit issue. The numbers frightened her.

Traditional cards charge between 2.25 and 2.33 percent on each purchase, plus 25 cents per purchase and several monthly fees, said Randall Greenwood, Elizabeth Ann’s general manager.

Typically, the profit margin on the sale of a gallon of gas is only 2 or 3 cents. On one recent delivery, Everett paid $1.89 per gallon and sold it for $1.91.

“I couldn’t make any money,” Everett said.

Then she discovered that her oil dealer, H.A. Mapes of Springvale, also ran a credit card co-op. Through it, she was able to reduce her per-purchase costs and reduce the monthly fees.

“Their rates were one quarter to one half of the banks,” she said.

For a 10-gallon purchase of gas, Mapes charged rates of 37.5 cents for a debit card purchase and 46 cents for a credit card purchase. And there were fewer added fees.

Last month, Everett pulled the “cash only” signs off the pumps and set up a card reader behind the counter.

“We’re slowly picking up speed,” she said. Business has risen enough to again hire a second cashier to handle the increase.

Has the credit card system paid for itself yet? Not quite, Everett said.

Summer will help. But financial stability will depend on whether people buy the other stuff she sells, perhaps buying a six-pack of soda instead of only one, or buying beer from her instead of a supermarket.

“I really hope to sell more 12-packs of beer,” she said.