Books have been written on this matter, and the conflict and ruckus about where the "hot" slot machines are installed in the casino are still bubbling – over 60 yrs after the slot machines were 1st added to the gaming floor in the casinos.
The standard rule is that the more favourable one armed bandits were positioned just inside the main entrance of the casino; so that casino fanatics walking by would be able to see jackpot winners and be enthralled to come into the casino … play. Our reasoning is that this is definitely no longer so.
Most of the major casinos presently are massive complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ slot machines near any doorways.
An additional classic rule is that loose slot games are put on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be influenced 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 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!
These days, casinos are constantly changing their philosophy about where to place the loose slot machine games.