Books have been written on this matter, and the debates and disagreement about where the "hot" slot games are installed in a casino are still intense – 60 yrs after slot machines were 1st placed in casinos.
The standard rule is that the superior slot games were put just inside the entrance of the casino; so that potential players passing by would see jackpot winners … be challenged to come inside and play. Our opinion is that this is definitely no longer the case.
The majority of the mega casinos today are colossal complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slot machines near to any entrances.
Another classic rule is that loose slot games are placed on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be energized to play. Importantly though, 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!
These days, casinos are constantly changing their philosophy about where to place the loose slots.