Volumes have been stated on this matter, and the controversy and ruckus about where the "hot" one armed bandits are located in the casino are still passionate – 60 years after slot games were 1st placed in gambling houses.
The classic rule is that the better slot machines were placed just inside the main entrance of the casino; so that potential players going by would be able to see jackpot winners … be stimulated to come inside … play. Our reckoning is that this is no longer true.
Practically all of the large casinos these days are oversized complexes and it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machine games close-by any doors.
An additional classic rule is that loose slots are located on the major aisles in the casinos, again so that more potential players could see winning jackpots and be inspired to play. Nonetheless, 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 machine 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!
These days, casinos are constantly changing their philosophy about where to place the loose one armed bandits.