Books have been written on this matter, and the debates and discord about where the "hot" slots are positioned in the casino are still on-going – sixty years after slot games were 1st installed in the casinos.
The quintessential rule is that the better slots were put just inside the main entrance of the casino; so that casino fanatics passing by would be able to see real jackpot winners … be baited to come inside and play. Our verdict is that this is not so anymore.
Most of the big name casinos nowadays are oversized complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ one armed bandits close to any doors.
Yet another classic rule is that loose slots are installed on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be energized to play. Interestingly 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 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 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 perspective about where to place the loose slots.