Volumes have been stated on this issue, and the disquiet and discussion about where the "hot" slot machines are placed in the casino are still passionate – 60 years after the slot machines were first placed in casinos.
The traditional rule is that the best one armed bandits were positioned just inside the main entrance of the casino; so that potential players going by would be able to see actual jackpot winners and be inspired to come inside and play. Our assessment is that this is definitely no longer the case.
The great majority of the major casinos nowadays are grand complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slots in close proximity to any of the doors.
An additional standard rule is that loose slot machines are positioned on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be motivated to play. Notably however, 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!
These days, casinos are constantly changing their philosophy about where to place the loose slot games.