Volumes have been said on this issue, and the contention and interchanges about where the "hot" slot machines are placed in a casino are still taking place – over sixty years after slot machines were first installed in gambling houses.
The quintessential rule is that the more favourable slot games were placed just inside the main doorway of the casino; so that people walking by would see actual jackpot winners and be impressed enough to come into the casino and play. Our observation is that this is no longer true.
Practically all of the big name casinos presently are grand complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slots in close proximity to any doors.
Another classic rule is that loose slot games are placed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be influenced to play. Notably 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 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!
In recent times, casinos are constantly changing their perspective about where to place the loose slot machines.