Books have been said on this topic, and the disquiet and ruckus about where the "hot" slot machine games are placed in a casino are still passionate – more than 60 yrs after one armed bandits were first installed in gambling dens.
The traditional rule is that the better slot games were put just inside the door of the casino; so that potential gamblers walking by would see real jackpot winners … be inspired to come into the casino and play. Our theory is that this is not so anymore.
Almost all of the large casinos nowadays are colossal complexes and it is not possible to see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot games close to any entrances or exits.
Yet another classic rule is that loose slot machines are placed on the major aisles inside the casinos, again so that more people could see winning jackpots and be motivated 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 the 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 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 one armed bandits.