Books have been set forth on this issue, and the bickering and discord about where the "hot" slot machines are placed in the casino are still ongoing – 60 years after slot machines were 1st installed in gambling houses.
The quintessential rule is that the better slot machines were put just inside the main doorway of the casino; so that individuals passing by would be able to see real jackpot winners and be titillated to come unto the gambling floor … play. Our standpoint is that this is not so anymore.
Many of the large casinos nowadays are monstrous complexes and it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot games in close proximity to any entrances or exits.
Another traditional rule is that loose slot games are placed on the major aisles in the casinos, again so that more people could see winning jackpots and be motivated to play. However, 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 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 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 philosophy about where to place the loose slot machine games.