Books have been set forth on this topic, and the disquiet and disharmony about where the "hot" slot machines are installed in a casino are still intense – sixty yrs after slot games were first installed in gambling houses.
The quintessential rule is that the superior slot machines were positioned just inside the main entry of the casino; so that casino fanatics going by would be able to see actual jackpot winners … be captivated to come unto the gaming floor … play. Our frame of mind is that this is definitely no longer true.
Most of the big name casinos nowadays are titanic complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slot machines near to any exits.
Another classic rule is that loose slot machine games are put on the major aisles inside the casinos, again so that more folks could see winning jackpots and be influenced 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 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!
Today, casinos are constantly changing their philosophy about where to place the loose one armed bandits.