Books have been stated on this matter, and the contention and squabbling about where the "hot" video slots are installed in the casino are still there – more than sixty yrs after one armed bandits were first added to the gaming floor in gambling dens.
The traditional rule is that the superior slot machine games were located just inside the main entrance of the casino; so that individuals passing by would see actual jackpot winners and be keen enough to come unto the gaming floor and play. Our reckoning is that this is definitely no longer so.
Practically all of the mega casinos these days are monstrous complexes and it is not possible to see inside from the sidewalk, so there’s no longer a reason to place the ‘loose’ one armed bandits in close proximity to any exits.
Yet another standard rule is that loose slot machines are positioned on the major aisles in the casinos, again so that more people could see winning jackpots and be encouraged to play. Interestingly 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 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.