Books have been written on this issue, and the conflict and disagreement about where the "hot" slot games are placed in a casino are still rampant – over 60 yrs after slot machines were first installed in the casinos.
The classic rule is that the superior slot machines were positioned just inside the main entryway of the casino; so that potential players passing by would be able to see jackpot winners … be possessed to come unto the gaming floor and play. Our inference is that this is no longer true.
Practically all of the major casinos nowadays are monstrous complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slot machines near to any doorways.
An additional standard rule is that loose slots are located on the major aisles inside the casinos, again so that more persons could see winning jackpots and be inspired to play. Importantly though, 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 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 slot machine games.