Books have been stated on this topic, and the debates and arguments about where the "hot" slot machines are placed in the casino are still raging – over sixty years after the slots were 1st added to the gaming floor in gambling houses.
The classic rule is that the superior slot machines were installed just inside the main entry of the casino; so that fun seekers going by would see jackpot winners and be captivated to come inside … play. Our sneaking suspicion is that this is definitely no longer so.
Nearly all of the mega casinos today are enormous complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ one armed bandits in close proximity to any doorways.
An additional standard rule is that loose slot machines are placed on the major aisles inside the casinos, again so that more folks could see winning jackpots and be encouraged to play. Importantly though, we find that this also isn’t 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 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!
These days, casinos are constantly changing their philosophy about where to place the loose one armed bandits.