Books have been written on this matter, and the disquiet and arguments about where the "hot" one armed bandits are placed in a casino are still on-going – over sixty years after one armed bandits were first added to the gaming floor in the casinos.
The classic rule is that the better slot games were put just inside the door of the casino; so that folks passing by would see real jackpot winners … be possessed to come into the casino … play. Our theory is that this is no longer true.
Just about all of the large casinos nowadays are titanic complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machine games near any of the doors.
An additional classic rule is that loose slots are installed on the major aisles in the casinos, again so that more potential players could see winning jackpots and be galvanized to play. Notably 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 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 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 perspective about where to place the loose slots.