Books have been stated on this subject, and the debates and discourse about where the "hot" slot machine games are installed in a casino are still bubbling – more than 60 yrs after slot machine games were first placed in gambling houses.
The traditional rule is that the better slot games were put just inside the main entrance of the casino; so that persons going by would be able to see actual jackpot winners and be enthralled to come unto the gaming floor … play. Our frame of mind is that this is not so anymore.
Most of the mega casinos nowadays are super-colossal complexes … now you can’t see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slot machine games close-by any exits.
Yet another traditional rule is that loose slot machine games are located on the major aisles inside the casinos, again so that more potential gamblers 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 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 slots.