While that is true, if you have equidistant from you two locations, one with one station, and one with four, then all other things being equal, you're going to go to the location with four stations - more price competition, less likelihood of queueing and the like.
Unfortunately, it could easily be the case that the mentioned price competition outweighs the value of increased traffic due to decreased queuing, given how incredibly small the margin on gas stations is (from what I've heard from friends that have managed them).
