Books have been set forth on this subject, and the debates and disagreement about where the "hot" video slots are installed in the casino are still passionate – more than sixty yrs after slot machines were first placed in gambling houses.
The quintessential rule is that the superior slot machines were put just inside the door of the casino; so that folks walking by would see real jackpot winners and be tempted to come inside and play. Our point of view is that this is definitely no longer so.
The great majority of the major casinos presently are herculean complexes … you can no longer see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ slot machines near to any of the doors.
Another traditional rule is that loose slot games are positioned on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Notably however, 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 one armed bandits 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.