Volumes have been stated on this issue, and the conflict and ruckus about where the "hot" slot machine games are placed in a casino are still on-going – over 60 yrs after slot machines were 1st placed in gambling houses.
The classic rule is that the most favorable slot games were located just inside the main doorway of the casino; so that individuals walking by would see real jackpot winners … be smitten to come unto the gaming floor … play. Our view is that this is definitely no longer so.
Practically all of the major casinos presently are titanic complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ one armed bandits close to any doors.
An additional classic rule is that loose slot machine games are installed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be motivated to play. Notably though, we find that this also isn’t 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 the slots 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 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 machines.