Books have been stated on this matter, and the conflict and discourse about where the "hot" slots are placed in a casino are still there – sixty yrs after slot machine games were first added to the gaming floor in the casinos.
The quintessential rule is that the more favourable slot machines were installed just inside the entry of the casino; so that fun seekers passing by would be able to see jackpot winners and be titillated to come unto the gambling floor … play. Our resolution is that this is definitely no longer true.
Nearly all of the big name casinos today are colossal complexes and it is not possible to see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot games close to any doorways.
An additional classic rule is that loose slot machine games are located on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Interestingly though, 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!
Today, casinos are constantly changing their philosophy about where to place the loose slot machine games.