We have a game store where you can go to play the board games and buy the ones you like. It's crowded but I don't know if people actually purchases things.
Its not a very profitable or well run convenience store compared to a real convenience store, but it does well enough. As do most FLGS that run friday night magic. I'm sure there are some that can't sell junk food due to zoning or ordinances, that must be annoying.
The problem is scaling it outside a couple hours Friday night. Another day of the week, six guys playing pathfinder on a card table makes the store look busy compared to a usually completely empty antique store, but what kind of revenue is rolling in per hour? You can pay the electric bill by selling monster energy drinks out of the cooler, but retail establishments have other bills to pay, and the antique store only needs one sale per week to pay their bills...