Books have been set forth on this topic, and the conflict and discourse about where the "hot" slots are installed in the casino are still taking place – over 60 yrs after slot machine games were first placed in the casinos.
The traditional rule is that the better slots were installed just inside the main entry of the casino; so that everyone passing by would see real jackpot winners and be convinced to come inside and play. Our deduction is that this is no longer the case.
Practically all of the large casinos these days are giant complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ one armed bandits near to any doorways.
An additional classic rule is that loose slot machine games are located on the major aisles inside the casinos, again so that more people could see winning jackpots and be influenced 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 one armed bandits 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!
Today, casinos are constantly changing their philosophy about where to place the loose slot machine games.