Books have been stated on this issue, and the contention and discord about where the "hot" slot games are located in the casino are still taking place – more than sixty yrs after slot machines were 1st added to the gaming floor in casinos.
The classic rule is that the superior slots were put just inside the door of the casino; so that fun seekers walking by would see real jackpot winners … be captivated to come unto the gambling floor … play. Our inclination is that this is not so anymore.
Almost all of the major casinos presently are titanic complexes and it is not possible to see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slots near to any entrances.
Another classic rule is that loose slot machines are positioned on the major aisles in the casinos, again so that more folks could see winning jackpots and be encouraged to play. Importantly 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 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 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 philosophy about where to place the loose slot games.