Books have been said on this subject, and the conflict and ruckus about where the "hot" one armed bandits are positioned in the casino are still there – over 60 years after the slots were 1st placed in gambling dens.
The quintessential rule is that the most favorable slot machine games were put just inside the main entry of the casino; so that people passing by would see real jackpot winners and be influenced to come unto the gaming floor and play. Our resolution is that this is no longer the case.
Practically all of the large casinos nowadays are behemothic complexes … you can no longer see inside from the sidewalk, so there’s no longer a reason to put the ‘loose’ slot games near any entrances or exits.
Yet another traditional rule is that loose one armed bandits are put on the major aisles in the casinos, again so that more potential players could see winning jackpots and be galvanized to play. Importantly 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 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!
Nowadays, casinos are constantly changing their philosophy about where to place the loose slots.