Books have been said on this topic, and the bickering and discord about where the "hot" one armed bandits are located in the casino are still rampant – more than 60 years after the slot machines were 1st installed in the casinos.
The traditional rule is that the better slot games were installed just inside the main entry of the casino; so that individuals passing by would see real jackpot winners and be keen enough to come inside … play. Our inference is that this is not so anymore.
Nearly all of the large casinos presently are magnificent complexes and it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slot machines close to any doorways.
Yet another standard rule is that loose slot games are installed on the major aisles in the casinos, again so that more folks could see winning jackpots and be motivated 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 slots 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!
In recent times, casinos are constantly changing their perspective about where to place the loose slot games.