Books have been said on this subject, and the controversy and disagreement about where the "hot" slot machines are positioned in the casino are still happening – sixty years after the slots were 1st placed in casinos.
The traditional rule is that the best slot games were placed just inside the main foyer of the casino; so that potential players going by would be able to see real jackpot winners and be stimulated to come inside and play. Our inclination is that this is no longer true.
Most of the large casinos today are behemothic complexes and you no longer can see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot machine games near to any doorways.
Yet another traditional rule is that loose slot machines are installed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be energized to play. However, 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 one armed bandits 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 perspective about where to place the loose slot machines.