Books have been written on this matter, and the contention and discussion about where the "hot" slot machine games are placed in a casino are still bubbling – over 60 yrs after slot games were first installed in gambling houses.
The quintessential rule is that the best slot games were located just inside the door of the casino; so that casino fanatics going by would see real jackpot winners … be impressed enough to come inside … play. Our thought is that this is no longer the case.
Nearly all of the major casinos presently are enormous complexes … now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot machines near any entrances.
An additional standard rule is that loose slot machines are put on the major aisles in the casinos, again so that more people could see winning jackpots and be influenced to play. Notably 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 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 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 slots.