Books have been said on this matter, and the bickering and interchanges about where the "hot" slot machines are positioned in the casino are still on-going – over sixty yrs after one armed bandits were first placed in gambling houses.
The quintessential rule is that the best slot machine games were located just inside the main entryway of the casino; so that persons passing by would see jackpot winners and be aroused to come into the casino and play. Our assessment is that this is not so anymore.
The majority of the major casinos today are massive complexes and it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot machines close to any entrances or exits.
Another traditional rule is that loose slot games are positioned on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be energized to play. Nonetheless, 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 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 one armed bandits.