[sbierwagen]

The original quote is true, but he misphrased it.

The convenience store attached to a gas station is very profitable (huge markups on cheap food) but has relatively little revenue. The gasoline is not very profitable (razor thin margins due to competing with, essentially, everyone) but brings in a lot of revenue. (Every customer at a gas station buys gas)

The convenience store is the most profitable part, but that doesn't mean you can get rid of the gas pumps and just sell five dollar bottles of Coke.