Books have been written on this matter, and the debates and face-offs about where the "hot" one armed bandits are positioned in a casino are still passionate – 60 years after one armed bandits were first installed in gambling houses.
The classic rule is that the superior slots were located just inside the door of the casino; so that everyone going by would see actual jackpot winners and be impressed enough to come unto the gaming floor … play. Our sneaking suspicion is that this is not so anymore.
The majority of the big name casinos these days are humongous complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot games close to any exits.
An additional traditional rule is that loose one armed bandits are located on the major aisles in the casinos, again so that more people could see winning jackpots and be energized to play. Interestingly though, we find that this also is not 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 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 slot machines.