Books have been stated on this issue, and the debates and face-offs about where the "hot" one armed bandits are installed in the casino are still passionate – 60 years after the slot machines were first placed in gambling dens.
The quintessential rule is that the very best one armed bandits were put just inside the main entry of the casino; so that casino fanatics going by would see real jackpot winners and be smitten to come unto the gaming floor and play. Our disposition is that this is definitely no longer true.
Many of the big name casinos nowadays are humongous complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits near to any doors.
Another traditional rule is that loose slot games are placed on the major aisles in the casinos, again so that more people could see winning jackpots and be inspired to play. Notably 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose slot machine games.