Books have been written on this matter, and the disquiet and discussion about where the "hot" slots are located in the casino are still passionate – more than sixty years after one armed bandits were first placed in gambling dens.
The standard rule is that the better slots were put just inside the main door of the casino; so that potential players going by would be able to see jackpot winners … be mesmerized enough to come unto the gaming floor and play. Our conclusion is that this is no longer true.
The great majority of the major casinos presently are colossal complexes … you can no longer see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot machines close-by any doors.
An additional classic rule is that loose one armed bandits are positioned on the major aisles inside the casinos, again so that more people could see winning jackpots and be roused to play. 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 slot 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 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!
Nowadays, casinos are constantly changing their philosophy about where to place the loose slots.