Volumes have been said on this matter, and the conflict and ruckus about where the "hot" slot machines are located in the casino are still ongoing – more than 60 yrs after the slot machines were 1st installed in the casinos.
The standard rule is that the superior slot machines were installed just inside the entrance of the casino; so that individuals going by would be able to see real jackpot winners and be possessed to come unto the gambling floor and play. Our estimation is that this is no longer the case.
Most of the large casinos nowadays are massive complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ one armed bandits near to any exits.
An additional traditional rule is that loose slots are installed on the major aisles inside the casinos, again so that more people could see winning jackpots and be galvanized to play. However, 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 slot machine 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 slots.