[Andrew_nenakhov]

The rate of customers who make additional purchases is closer to 50%. Source: I know a guy who runs a gas station. Profits from additional sales are bigger than from selling gas: they have 3-4% margin selling gas and 30-70% margin selling additional products. Coffee, wiping cloths, chocolate bars, etc.

[refurb]

I used to work in a gas station during high school and did the paper work for the owner each morning.

He was a franchise, so his gas margin was even lower, closer to 1-2%. And yes, most of the profit came from inside sales where the margins were 50%+ or higher.

[brewdad]

This has to vary greatly based on location. I almost always go inside gas stations along a freeway trip. I don't know that I've been inside a "local" station in 15 years unless the real purpose of the trip was to grab a Powerball ticket and the gas fill-up was incidental. So maybe five times total.