Books have been said on this matter, and the contention and interchanges about where the "hot" slot machines are located in a casino are still happening – more than 60 years after slots were 1st placed in gambling dens.
The standard rule is that the very best slots were located just inside the main entry of the casino; so that casino fanatics walking by would be able to see real jackpot winners and be convinced to come unto the gaming floor … play. Our sentiment is that this is definitely no longer so.
Practically all of the major casinos presently are oversized complexes … you no longer can see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits close-by any entrances or exits.
An additional classic 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 inspired to play. Notably however, 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 the 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot games.