Books have been written on this matter, and the contention and ruckus about where the "hot" video slots are placed in the casino are still intense – more than 60 years after the slots were 1st added to the gaming floor in gambling houses.
The standard rule is that the very best slots were positioned just inside the entry of the casino; so that potential gamblers walking by would see jackpot winners … be impressed enough to come inside and play. Our perspective is that this is definitely no longer so.
Nearly all of the major casinos these days are mammoth complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slots close to any exits.
Another standard rule is that loose slot machines are positioned on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be roused to play. Interestingly though, 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 slot games 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 one armed bandits.