For millions of Costco members, filling up their gas tank is almost as much a part of the warehouse club experience as buying bulk groceries or oversized packages of paper towels. Costco gas stations are often packed with drivers willing to wait in line, and many members go out of their way to fill up there because the prices are usually lower than nearby competitors.
But Costco isn't necessarily trying to make huge profits from every gallon of fuel it sells. The reason the company can offer cheaper gas comes down to a business strategy that goes far beyond the pump.
