Books have been written on this subject, and the bickering and disharmony about where the "hot" slot games are placed in the casino are still rampant – over 60 years after slot games were first placed in gambling houses.
The quintessential rule is that the most favorable slot machine games were installed just inside the entrance of the casino; so that fun seekers passing by would be able to see jackpot winners … be inspired to come unto the gambling floor and play. Our resolution is that this is definitely no longer so.
Practically all of the large casinos these days are gigantic complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ one armed bandits in close proximity to any entrances.
Another traditional rule is that loose slot games are positioned on the major aisles in the casinos, again so that more potential players could see winning jackpots and be encouraged 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!
These days, casinos are constantly changing their philosophy about where to place the loose slots.