Books have been written on this topic, and the debates and interchanges about where the "hot" slot machine games are positioned in a casino are still intense – more than sixty years after slot machines were first placed in casinos.
The classic rule is that the very best slot machines were put just inside the main entrance of the casino; so that individuals going by would see actual jackpot winners and be smitten to come unto the gambling floor and play. Our point of view is that this is no longer true.
Many 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 have the ‘loose’ slot machine games near to any entrances or exits.
Yet another classic rule is that loose slot machine games are put on the major aisles inside the casinos, again so that more folks could see winning jackpots and be encouraged 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose one armed bandits.