Books have been stated on this subject, and the controversy and ruckus about where the "hot" one armed bandits are located in a casino are still on-going – over sixty years after slot machines were first placed in gambling houses.
The traditional rule is that the more favourable one armed bandits were put just inside the door of the casino; so that everyone walking by would be able to see real jackpot winners … be influenced to come unto the gambling floor and play. Our disposition is that this is definitely no longer the case.
Most of the big name casinos presently are magnificent complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot machines in close proximity to any entrances or exits.
Another classic rule is that loose slot games are put on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be motivated to play. Importantly however, 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 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 perspective about where to place the loose slot games.