Books have been said on this matter, and the contention and discussion about where the "hot" video slots are installed in a casino are still happening – more than 60 yrs after the slot machines were first placed in gambling houses.
The classic rule is that the best one armed bandits were put just inside the main entrance of the casino; so that potential gamblers passing by would see real jackpot winners … be mesmerized enough to come unto the gambling floor and play. Our view is that this is no longer true.
Just about all of the mega casinos today are gigantic complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ one armed bandits close-by any entrances.
Another classic rule is that loose one armed bandits are positioned on the major aisles inside the casinos, again so that more people could see winning jackpots and be encouraged 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 slot machine games 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 philosophy about where to place the loose one armed bandits.