Books have been stated on this matter, and the bickering and ruckus about where the "hot" slot machine games are installed in a casino are still taking place – over 60 years after slot games were first installed in casinos.
The classic rule is that the very best slot games were put just inside the main entrance of the casino; so that persons walking by would see real jackpot winners and be challenged to come unto the gaming floor … play. Our philosophy is that this is no longer true.
Just about all of the major casinos these days are enormous complexes … now you can’t see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot machine games near to any entrances.
An additional traditional rule is that loose slots are placed on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be roused to play. Importantly however, 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 machine 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 very 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 philosophy about where to place the loose slot games.