Books have been said on this subject, and the debates and arguments about where the "hot" slot machines are positioned in a casino are still taking place – sixty years after slot games were first placed in the casinos.
The standard rule is that the very best slot machines were placed just inside the main door of the casino; so that people going by would see actual jackpot winners … be smitten to come unto the gaming floor and play. Our disposition is that this is no longer the case.
Many of the large casinos nowadays are monstrous complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot games near to any doorways.
Another standard rule is that loose one armed bandits are placed on the major aisles in the casinos, again so that more persons could see winning jackpots and be influenced to play. Notably though, 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 the slots 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!
These days, casinos are constantly changing their perspective about where to place the loose one armed bandits.