Books have been stated on this subject, and the contention and interchanges about where the "hot" slot machines are located in a casino are still happening – over sixty years after the slots were first placed in the casinos.
The traditional rule is that the best one armed bandits were located just inside the entrance of the casino; so that casino fanatics passing by would see real jackpot winners … be intrigued enough to come unto the gaming floor … play. Our theory is that this is definitely no longer so.
Just about all of the large casinos these days are humongous complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot games in close proximity to any exits.
Another classic rule is that loose slot games are placed on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be roused to play. Notably however, we find that this also is no longer a universal rule.
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!
In recent times, casinos are constantly changing their perspective about where to place the loose slot machines.