I used to know a family who ran a gas station in my city. I was surprised to learn they made almost nothing from the sale of fuel. The actual profit -- to them -- was in the convenience store goods they sold.
I'm not sure who eats the cost of the theft, but I'm guessing it's the same people that make almost no money from the sale of the fuel. These were not wealthy people; they were working obscene hours and barely scraping by.