Books have been said on this issue, and the disquiet and disharmony about where the "hot" slot machine games are installed in a casino are still on-going – over 60 years after slot machines were 1st placed in the casinos.
The traditional rule is that the better slot machine games were located just inside the main entrance of the casino; so that persons going by would see real jackpot winners and be captivated to come inside and play. Our presumption is that this is not so anymore.
Just about all of the mega casinos these days are massive complexes … you no longer can see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits near any doorways.
Yet another standard rule is that loose slot machine games are located on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be inspired to play. Importantly 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 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 one armed bandits.