Volumes have been written on this topic, and the conflict and disagreement about where the "hot" one armed bandits are installed in a casino are still bubbling – sixty yrs after the slot machines were first installed in casinos.
The classic rule is that the most favorable slot machines were installed just inside the main door of the casino; so that individuals going by would be able to see actual jackpot winners … be challenged to come unto the gaming floor and play. Our philosophy is that this is definitely no longer the case.
The majority of the large casinos nowadays are monstrous complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot games near any doorways.
An additional standard rule is that loose slots are put on the major aisles in the casinos, again so that more people could see winning jackpots and be energized to play. Importantly 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 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 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 philosophy about where to place the loose slot machine games.