Ryan Dancey says you can target gamers by how good their transportation options are and how much disposable income they have.
In other words... the more money you have for other entertainment, or the more transportation options you have (to get to entertainment), the less likely you are to game.
Soooo... does this mean gaming is inherently sub-optimal?
Keep in mind, it requires BOTH to make you likely to be a gamer.
In other words, if you have transportation but no money, you STILL aren't likely to game. You go find a museum or a *shudder* a park.