Books have been said on this subject, and the controversy and discussion about where the "hot" slots are placed in the casino are still ongoing – over 60 yrs after the slots were 1st added to the gaming floor in the casinos.
The classic rule is that the most favorable slots were positioned just inside the main entry of the casino; so that potential gamblers going by would see actual jackpot winners … be impressed enough to come into the casino and play. Our stance is that this is not so anymore.
Nearly all of the mega casinos presently are giant complexes … you can no longer see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slot machines near to any entrances or exits.
Another traditional rule is that loose slot games are installed on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be encouraged to play. Interestingly though, 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 the slot machines 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 one armed bandits.