Volumes have been written on this matter, and the disquiet and face-offs about where the "hot" one armed bandits are placed in a casino are still on-going – more than 60 years after one armed bandits were first added to the gaming floor in the casinos.
The classic rule is that the very best slot machines were put just inside the main entry of the casino; so that individuals passing by would be able to see jackpot winners and be intrigued enough to come unto the gaming floor … play. Our observation is that this is no longer the case.
Most of the large casinos nowadays are oversized complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ one armed bandits near to any doors.
An additional traditional rule is that loose slots are located on the major aisles inside the casinos, again so that more folks could see winning jackpots and be influenced to play. Importantly 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 slot machines 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!
Today, casinos are constantly changing their perspective about where to place the loose one armed bandits.