Volumes have been written on this matter, and the contention and discourse about where the "hot" slot machine games are located in the casino are still ongoing – 60 years after the slot machines were 1st placed in gambling houses.
The quintessential rule is that the very best slots were installed just inside the main entrance of the casino; so that potential players walking by would see real jackpot winners … be intrigued enough to come into the casino and play. Our standpoint is that this is definitely no longer true.
Most of the mega casinos nowadays are massive complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slot machine games close-by any exits.
Another traditional rule is that loose slot games are put on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be inspired to play. Notably 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 the slot machines 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 machines.