Books have been set forth on this matter, and the disquiet and discord about where the "hot" one armed bandits are installed in the casino are still on-going – over 60 yrs after slot games were first installed in gambling dens.
The quintessential rule is that the very best slot machine games were installed just inside the door of the casino; so that individuals passing by would see real jackpot winners … be smitten to come unto the gaming floor … play. Our reasoning is that this is definitely no longer the case.
Many of the large casinos these days are mammoth complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slots close to any entrances or exits.
Another classic rule is that loose slot games are installed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be encouraged to play. However, 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 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 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 slots.