Books have been said on this issue, and the disquiet and arguments about where the "hot" one armed bandits are placed in a casino are still on-going – over 60 years after slot machines were 1st placed in the casinos.
The quintessential rule is that the superior one armed bandits were placed just inside the main entry of the casino; so that casino fanatics walking by would see actual jackpot winners and be inspired to come unto the gaming floor … play. Our speculation is that this is not so anymore.
Most of the major casinos today are monstrous complexes … it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slots close to any entrances.
Another standard rule is that loose slots are installed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Nonetheless, 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 the slot machines 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 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 games.