Books have been said on this item, and the disquiet and ruckus about where the "hot" slot games are located in the casino are still ongoing – sixty yrs after slot machines were first placed in casinos.
The quintessential rule is that the superior slot machines were put just inside the main door of the casino; so that potential players passing by would see actual jackpot winners and be drawn to come unto the gambling floor … play. Our belief is that this is not so anymore.
Many of the major casinos presently are grand complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ one armed bandits near to any doorways.
An additional standard rule is that loose one armed bandits are placed 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 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!
These days, casinos are constantly changing their perspective about where to place the loose slot machine games.