Volumes have been written on this matter, and the disquiet and discussion about where the "hot" slot machine games are positioned in the casino are still happening – sixty years after slots were first placed in casinos.
The quintessential rule is that the superior one armed bandits were placed just inside the door of the casino; so that individuals passing by would see jackpot winners and be attracted to come unto the gambling floor and play. Our resolution is that this is definitely no longer so.
Most of the large casinos these days are herculean complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ one armed bandits in close proximity to any entrances or exits.
An additional classic rule is that loose slot machines are installed on the major aisles in the casinos, again so that more people could see winning jackpots and be galvanized to play. Notably though, 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 slot machine games 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.