Books have been said on this matter, and the disquiet and interchanges about where the "hot" slot machine games are located in the casino are still taking place – more than sixty yrs after slot machine games were first placed in casinos.
The traditional rule is that the most favorable one armed bandits were installed just inside the entrance of the casino; so that people going by would see jackpot winners and be baited to come unto the gaming floor … play. Our frame of mind is that this is definitely no longer the case.
The great majority of the big name casinos presently are magnificent complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot games near to any of the doors.
Another classic rule is that loose slots are put on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be galvanized 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 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 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 philosophy about where to place the loose slot games.