Volumes have been stated on this issue, and the disquiet and discussion about where the "hot" slot machine games are located in the casino are still ongoing – 60 years after slot machines were first installed in casinos.
The traditional rule is that the superior slots were positioned just inside the main entry of the casino; so that fun seekers passing by would see real jackpot winners and be enticed to come inside and play. Our observation is that this is not so anymore.
Nearly all of the major casinos presently are huge complexes and you no longer can see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ one armed bandits near to any doorways.
Another standard rule is that loose one armed bandits are placed on the major aisles inside the casinos, again so that more folks could see winning jackpots and be motivated 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot games.