Books have been written on this matter, and the disquiet and ruckus about where the "hot" slot machines are located in the casino are still ongoing – over sixty years after the slot machines were 1st installed in gambling houses.
The traditional rule is that the superior one armed bandits were positioned just inside the entrance of the casino; so that persons walking by would be able to see actual jackpot winners and be mesmerized enough to come unto the gaming floor … play. Our determination is that this is no longer true.
Almost all of the mega casinos nowadays are grand complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits in close proximity to any doorways.
Another standard rule is that loose one armed bandits are installed on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be energized to play. Notably however, 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 machine 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot machines.