On average it isn't true. The average profit margin is 1.4% for gas stations in the US. Clearly the majority are not making much money on gas. Presumably that low average could mean for many gas is a loss leader.

Which is greater than zero, contra the top-level comment.

not actually contra. Those extra cents selling at retail prices need a lot of volume to break even given employees, property taxes, maintenance. That's why there is always something on the property to sell- convenience store, car mechanic garage, car wash, even whole restaurants sometimes.

It will be even more true for EVs because the charging times are longer. You won't stop in the convenience store while you're charging your car, you'll want to charge your car while you're at a store or out to eat because it takes longer to charge than to get gas.

IMHO the charger networks are a short-term solution and will ultimately go away. It's not that they are all making money by marking up electrons, it's that they're inconvenient.

I know people that have "all the apps" installed on their phone because they want to use whatever charger is nearby, not necessarily one on a particular network. As these things become more ubiquitous, people are going to want to pay via cash or credit in addition to using their phone. Your local restaurant doesn't need their chargers to be on a national network, they need them to be run by a local guy who also handles maintenance - like arcade game operators in the 80's or your local vending machine company today.

That's my understanding, yes. The profit margins on the convenience items are just so much higher. 20oz bottle of soda? $2. Wholesale price, probably under $0.50.