Books have been written on this matter, and the conflict and discussion about where the "hot" slots are positioned in the casino are still intense – over sixty yrs after one armed bandits were 1st installed in gambling dens.
The classic rule is that the superior slot machine games were installed just inside the main entryway of the casino; so that fun seekers walking by would see real jackpot winners and be infatuated enough to come unto the gaming floor and play. Our perspective is that this is no longer true.
Almost all of the major casinos today are gigantic complexes … now you can’t see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ one armed bandits close to any of the doors.
Another standard rule is that loose slot machines are put on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be energized to play. Importantly however, we find that this also isn’t 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 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 games.