Volumes have been said on this issue, and the contention and ruckus about where the "hot" slot games are installed in a casino are still intense – over 60 yrs after slot machines were first added to the gaming floor in gambling houses.
The standard rule is that the more favourable slot machines were placed just inside the main door of the casino; so that potential gamblers walking by would see real jackpot winners … be inspired to come unto the gambling floor … play. Our estimation is that this is no longer the case.
Practically all of the mega casinos these days are super-colossal complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot machines close to any of the doors.
An additional traditional rule is that loose slot games are put on the major aisles inside the casinos, again so that more people could see winning jackpots and be encouraged 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot games.