Books have been said on this topic, and the conflict and discord about where the "hot" slot machines are located in a casino are still bubbling – sixty years after the slots were first placed in gambling dens.
The traditional rule is that the best slots were placed just inside the main entryway of the casino; so that potential gamblers going by would be able to see jackpot winners and be titillated to come into the casino … play. Our sneaking suspicion is that this is definitely no longer the case.
Most of the major casinos these days are giant complexes and you can no longer see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slot machine games near any entrances or exits.
An additional traditional rule is that loose slots are put on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be inspired to play. Notably though, we find that this also is not 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 philosophy about where to place the loose slot machine games.
