Books have been said on this subject, and the conflict and face-offs about where the "hot" one armed bandits are placed in a casino are still intense – sixty yrs after slot games were 1st placed in the casinos.
The quintessential rule is that the very best slot machine games were placed just inside the main doorway of the casino; so that folks going by would see jackpot winners and be aroused to come into the casino and play. Our viewpoint is that this is no longer true.
Almost all of the large casinos nowadays are mammoth complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machine games close-by any of the doors.
Another traditional rule is that loose slot machine games are put on the major aisles in the casinos, again so that more people could see winning jackpots and be encouraged 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 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 perspective about where to place the loose slot games.