Books have been written on this topic, and the debates and squabbling about where the "hot" slot games are positioned in a casino are still happening – over sixty years after slots were 1st placed in the casinos.
The traditional rule is that the better slots were placed just inside the door of the casino; so that potential gamblers walking by would be able to see actual jackpot winners and be mesmerized enough to come inside … play. Our disposition is that this is no longer true.
Most of the big name casinos presently are magnificent complexes and you no longer can see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slot machine games close-by any of the doors.
An additional standard rule is that loose slot machine games are positioned on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be galvanized to play. Importantly though, we find that this also is no longer a universal rule.
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 slot machines 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose one armed bandits.