Books have been stated on this issue, and the disquiet and disagreement about where the "hot" slot games are located in a casino are still intense – over 60 years after the slots were first placed in gambling houses.
The standard rule is that the most favorable slot machines were installed just inside the main foyer of the casino; so that folks going by would see jackpot winners … be titillated to come inside and play. Our observation is that this is definitely no longer true.
Many of the major casinos these days are massive complexes … now you can’t see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slot games near any of the doors.
An additional classic rule is that loose slot machine games are positioned on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Notably 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 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!
These days, casinos are constantly changing their perspective about where to place the loose slot machines.