Greg Furrier, a principal with Picor Commercial Real Estate Services has worked with QuikTrip identifying potential store locations in the Tucson marketplace. "Competitors fear them," he told the newspaper. "People hear they are going into the market, and they will sometimes go in and try to compete with them with sites, or bulk up with their existing locations."

QuikTrip "will start turning ground" for stores in Tucson this summer, spokesman Mike Thornbrugh told the newspaper, without revealing any specific locations. With regard to Circle K's purported response, he told the newspaper it's healthy for the marketplace and, beyond that, not something they are monitoring closely.

"Honestly, we are just going to concentrate on what QuikTrip does," he is quoted as saying. "We are concentrating on what we can do in our marketplace. We are going to have locations that in our opinion are going to be great."

Both QuikTrip and Couche-Tard are facing growing competition from Tesco's Fresh N Easy chain, which has been rapidly deploying 10,000 square-foot mini grocery stores with lots of private label and prepared foods that do not include gas but still threaten to take food revenue business from both larger format grocery stores and smaller format convenience stores. Fresh & Easy stores are now well deployed in Phoenix, Las Vegas and Southern and Northern California and Tesco continues to open stores at a pace of three a week.

"What's happening is these mini-marts or c-stores are starting to fill in those gaps that are left by those grocery stores that are also getting larger," Scott Testa, marketing professor at St. Joseph's University in Philadelphia, told the newspaper. "It's the traditional-grocery-store concept that is actually getting larger, and the mini-marts are growing into that kind of void that is left by these supermarkets. It seems like everything is getting larger."