Books have been set forth on this topic, and the disquiet and discussion about where the "hot" slot machines are placed in the casino are still ongoing – over sixty yrs after the slot machines were first added to the gaming floor in gambling dens.
The standard rule is that the more favourable slots were positioned just inside the main entrance of the casino; so that people passing by would see real jackpot winners … be inspired to come unto the gaming floor and play. Our theorem is that this is definitely no longer true.
Most of the major casinos these days are giant complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slots near any entrances or exits.
Another classic rule is that loose one armed bandits are placed on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be galvanized to play. Nonetheless, we find that this also isn’t 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 one armed bandits 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 philosophy about where to place the loose one armed bandits.