Books have been stated on this subject, and the conflict and ruckus about where the "hot" slots are placed in the casino are still on-going – more than sixty years after the slots were 1st placed in gambling dens.
The classic rule is that the very best one armed bandits were located just inside the main entry of the casino; so that casino fanatics going by would see jackpot winners and be infatuated enough to come unto the gambling floor and play. Our inference is that this is definitely no longer the case.
Nearly all of the large casinos presently are jumbo complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to put the ‘loose’ slot machine games close-by any of the doors.
Another standard rule is that loose slots are installed on the major aisles in the casinos, again so that more potential players could see winning jackpots and be encouraged to play. Nonetheless, 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 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose slots.