Volumes have been written on this matter, and the contention and interchanges about where the "hot" slot machines are located in the casino are still bubbling – sixty years after one armed bandits were first placed in gambling houses.
The quintessential rule is that the best one armed bandits were placed just inside the main door of the casino; so that folks walking by would be able to see jackpot winners and be challenged to come into the casino and play. Our presumption is that this is not so anymore.
Nearly all of the mega casinos today are herculean complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot machines near to any of the doors.
Yet another traditional rule is that loose one armed bandits are installed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be inspired 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 slot games 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!
Today, casinos are constantly changing their perspective about where to place the loose slot games.