Books have been said on this issue, and the bickering and discussion about where the "hot" slots are installed in a casino are still happening – more than 60 years after slot machine games were first added to the gaming floor in the casinos.
The quintessential rule is that the more favourable slot machines were placed just inside the main foyer of the casino; so that potential players going by would be able to see jackpot winners and be influenced to come unto the gambling floor … play. Our assessment is that this is definitely no longer so.
Most of the big name casinos today are monstrous complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ one armed bandits in close proximity to any exits.
Another standard rule is that loose slots are positioned on the major aisles in the casinos, again so that more folks could see winning jackpots and be galvanized to play. Nonetheless, 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 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot machines.