Books have been said on this item, and the controversy and squabbling about where the "hot" slot machines are installed in a casino are still bubbling – sixty years after the slot machines were 1st placed in gambling dens.
The classic rule is that the better slot machine games were installed just inside the main door of the casino; so that fun seekers going by would be able to see jackpot winners … be enticed to come unto the gambling floor … play. Our frame of mind is that this is no longer true.
The great majority of the big name casinos nowadays are monstrous complexes and it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to put the ‘loose’ slots close-by any of the doors.
Another traditional rule is that loose one armed bandits are positioned on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be galvanized to play. Notably however, 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 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 philosophy about where to place the loose slots.