Books have been said on this topic, and the conflict and face-offs about where the "hot" slot machine games are located in a casino are still rampant – over sixty years after slot games were first placed in gambling houses.
The classic rule is that the better slot machine games were located just inside the door of the casino; so that fun seekers going by would be able to see real jackpot winners and be mesmerized enough to come inside and play. Our theory is that this is no longer true.
Practically all of the large casinos these days are massive complexes … you can no longer see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slots near to any of the doors.
Another standard rule is that loose slot machine games are placed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be motivated to play. Notably however, we find that this also is not a universal rule any more.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played slots at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the very last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
Today, casinos are constantly changing their perspective about where to place the loose one armed bandits.