Volumes have been set forth on this subject, and the debates and disagreement about where the "hot" slot machines are installed in a casino are still there – over 60 years after one armed bandits were 1st installed in casinos.
The quintessential rule is that the more favourable slot machine games were placed just inside the main entryway of the casino; so that individuals walking by would be able to see real jackpot winners and be tempted to come into the casino … play. Our disposition is that this is definitely no longer the case.
Most of the large casinos today are giant complexes and you no longer can see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot machines close to any entrances or exits.
Another traditional rule is that loose slot machines are installed on the major aisles in the casinos, again so that more folks could see winning jackpots and be influenced to play. Nonetheless, 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 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!
Today, casinos are constantly changing their philosophy about where to place the loose one armed bandits.