Books have been set forth on this topic, and the contention and discord about where the "hot" one armed bandits are installed in a casino are still there – 60 yrs after slot machines were first added to the gaming floor in gambling houses.
The quintessential rule is that the most favorable slot machines were located just inside the door of the casino; so that persons passing by would see jackpot winners … be infatuated enough to come into the casino and play. Our thought is that this is definitely no longer so.
The great majority of the mega casinos presently are humongous complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot machines close to any entrances or exits.
An additional standard rule is that loose slot games are located on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be energized to play. Notably though, 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 slot machine games 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 perspective about where to place the loose slots.