Books have been set forth on this subject, and the debates and disagreement about where the "hot" one armed bandits are located in the casino are still ongoing – over 60 yrs after the slots were first added to the gaming floor in gambling houses.
The standard rule is that the more favourable slot machines were positioned just inside the entry of the casino; so that folks going by would see jackpot winners … be challenged to come unto the gambling floor … play. Our reckoning is that this is no longer the case.
Just about all of the mega casinos today are titanic 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 any entrances.
Another traditional rule is that loose slot games are placed on the major aisles inside the casinos, again so that more folks could see winning jackpots and be roused to play. Notably though, we find that this also is not 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!
Nowadays, casinos are constantly changing their philosophy about where to place the loose slot games.