Books have been said on this issue, and the controversy and discourse about where the "hot" slot machines are placed in the casino are still ongoing – over sixty yrs after the slot machines were 1st placed in gambling dens.
The traditional rule is that the more favourable slot games were put just inside the main doorway of the casino; so that people going by would see real jackpot winners and be keen enough to come inside … play. Our position is that this is no longer true.
The great majority of the large casinos presently are mammoth complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ one armed bandits in close proximity to any exits.
An additional classic rule is that loose slot games are positioned on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be inspired 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 slots 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 very 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 perspective about where to place the loose slot machine games.