Books have been stated on this subject, and the conflict and ruckus about where the "hot" slot machines are located in a casino are still intense – 60 years after slot machines were first installed in gambling dens.
The quintessential rule is that the more favourable slot machines were installed just inside the main doorway of the casino; so that potential players going by would be able to see jackpot winners and be stimulated to come unto the gambling floor … play. Our interpretation is that this is no longer true.
Just about all of the major casinos presently are huge complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ one armed bandits close to any entrances.
Yet another standard rule is that loose slot games are installed on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be energized 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.