Volumes have been set forth on this matter, and the debates and face-offs about where the "hot" slot machines are placed in the casino are still there – sixty years after the slot machines were 1st placed in gambling houses.
The traditional rule is that the more favourable slot machines were put just inside the main door of the casino; so that fun seekers going by would be able to see real jackpot winners … be inspired to come inside and play. Our interpretation is that this is not so anymore.
The great majority of the big name casinos these days are magnificent complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits close-by any of the doors.
Another traditional rule is that loose one armed bandits are put on the major aisles inside the casinos, again so that more folks could see winning jackpots and be motivated to play. Notably 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 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!
Today, casinos are constantly changing their perspective about where to place the loose one armed bandits.