Books have been written on this issue, and the bickering and disagreement about where the "hot" slot machines are placed in the casino are still passionate – more than 60 yrs after the slots were 1st placed in the casinos.
The standard rule is that the very best slot machines were placed just inside the main entryway of the casino; so that folks passing by would be able to see real jackpot winners … be enthralled to come unto the gaming floor … play. Our sneaking suspicion is that this is definitely no longer the case.
Nearly all of the major casinos today are behemothic complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slot machine games in close proximity to any exits.
Yet another classic rule is that loose slot machine games are put on the major aisles inside the casinos, again so that more persons could see winning jackpots and be influenced to play. Importantly 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 the 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!
In recent times, casinos are constantly changing their perspective about where to place the loose slot games.