Volumes have been written on this matter, and the contention and disharmony about where the "hot" slot machines are placed in the casino are still taking place – over sixty years after the slots were first installed in casinos.
The standard rule is that the better slot machine games were located just inside the door of the casino; so that persons passing by would see actual jackpot winners … be stimulated to come inside … play. Our frame of mind is that this is definitely no longer true.
Nearly all of the major casinos nowadays are behemothic complexes … now you can’t see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slots close-by any exits.
Yet another standard rule is that loose slot machine games are put on the major aisles in the casinos, again so that more people could see winning jackpots and be inspired 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 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose slot machines.