Books have been said on this topic, and the disquiet and feuds about where the "hot" video slots are placed in a casino are still on-going – over sixty yrs after slot machine games were 1st added to the gaming floor in the casinos.
The classic rule is that the better slot machines were positioned just inside the entry of the casino; so that casino fanatics going by would see real jackpot winners … be inspired to come unto the gaming floor … play. Our persuasion is that this is definitely no longer so.
Almost all of the mega casinos nowadays are behemothic complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slots close to any doorways.
An additional classic rule is that loose slots are installed on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be encouraged 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.