Books have been written on this item, and the disquiet and discourse about where the "hot" slot machine games are placed in the casino are still happening – sixty years after the slot machines were first added to the gaming floor in casinos.
The standard rule is that the very best one armed bandits were put just inside the door of the casino; so that potential gamblers walking by would see actual jackpot winners and be inspired to come unto the gambling floor and play. Our estimation is that this is definitely no longer the case.
Practically all of the major casinos these days are colossal complexes … now you can’t see inside from the sidewalk, so there’s no longer a reason to put the ‘loose’ slots near any doorways.
An additional standard rule is that loose slots are placed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Nonetheless, 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 philosophy about where to place the loose slot machine games.