Books have been written on this topic, and the contention and disharmony about where the "hot" slots are placed in a casino are still raging – more than 60 yrs after the slot machines were 1st installed in the casinos.
The classic rule is that the most favorable slot machine games were located just inside the door of the casino; so that fun seekers passing by would see real jackpot winners and be inspired to come unto the gambling floor … play. Our attitude is that this is definitely no longer so.
Practically all of the large casinos presently are giant complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ one armed bandits near any entrances or exits.
Yet another standard rule is that loose one armed bandits are put on the major aisles in the casinos, again so that more potential players could see winning jackpots and be inspired to play. Importantly though, we find that this also is no longer a universal rule.
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 slot machines 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!
Nowadays, casinos are constantly changing their philosophy about where to place the loose one armed bandits.