Volumes have been stated on this item, and the controversy and squabbling about where the "hot" slot machine games are placed in a casino are still on-going – more than sixty years after the slot machines were 1st placed in gambling houses.
The quintessential rule is that the very best one armed bandits were placed just inside the main entryway of the casino; so that persons walking by would see jackpot winners and be infatuated enough to come unto the gaming floor and play. Our deduction is that this is no longer the case.
Practically all of the large casinos presently are grand complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot machines near any doorways.
Another classic rule is that loose slot games are installed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be influenced to play. Importantly 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 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 slot machine games.