Books have been written on this issue, and the debates and discourse about where the "hot" slot machines are located in a casino are still taking place – 60 yrs after slots were 1st installed in casinos.
The quintessential rule is that the very best one armed bandits were positioned just inside the entry of the casino; so that individuals walking by would see jackpot winners … be inspired to come unto the gaming floor and play. Our stance is that this is definitely no longer true.
Practically all of the major casinos today are colossal complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slot machines in close proximity to any entrances.
An additional traditional rule is that loose one armed bandits are put on the major aisles in the casinos, again so that more potential players could see winning jackpots and be roused 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!
These days, casinos are constantly changing their philosophy about where to place the loose slots.