Books have been said on this topic, and the controversy and disharmony about where the "hot" one armed bandits are installed in a casino are still there – more than sixty yrs after slots were first installed in gambling houses.
The traditional rule is that the better slot machine games were put just inside the main doorway of the casino; so that potential players passing by would see actual jackpot winners … be tempted to come inside and play. Our finding is that this is definitely no longer so.
Practically all of the big name casinos nowadays are oversized complexes and it is not possible to see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ slot machines close-by any doorways.
Another classic rule is that loose one armed bandits are positioned on the major aisles inside the casinos, again so that more people could see winning jackpots and be energized to play. Importantly 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 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 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!
In recent times, casinos are constantly changing their perspective about where to place the loose slot machines.