Volumes have been set forth on this subject, and the debates and disharmony about where the "hot" slot machine games are placed in the casino are still rampant – sixty years after slots were first placed in the casinos.
The standard rule is that the most favorable slot machines were placed just inside the main foyer of the casino; so that people passing by would be able to see actual jackpot winners and be possessed to come unto the gambling floor … play. Our disposition is that this is definitely no longer true.
The great majority of the major casinos nowadays are humongous complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machines near any entrances.
Another traditional rule is that loose slots are installed on the major aisles in the casinos, again so that more people could see winning jackpots and be roused to play. Notably 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slots.