Books have been stated on this topic, and the conflict and interchanges about where the "hot" video slots are located in a casino are still rampant – over sixty yrs after slot games were first installed in casinos.
The standard rule is that the best slot games were positioned just inside the main foyer of the casino; so that individuals passing by would see jackpot winners and be mesmerized enough to come unto the gambling floor and play. Our interpretation is that this is no longer true.
Many of the large casinos these days are enormous complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot machines in close proximity to any exits.
An additional classic rule is that loose slot games are placed on the major aisles in the casinos, again so that more potential players could see winning jackpots and be influenced to play. Importantly 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 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 perspective about where to place the loose slots.