Books have been stated on this topic, and the bickering and squabbling about where the "hot" slot machine games are placed in the casino are still ongoing – more than sixty years after slots were first placed in gambling dens.
The quintessential rule is that the very best slot machine games were located just inside the main doorway of the casino; so that potential players walking by would be able to see jackpot winners … be captivated to come inside … play. Our view is that this is no longer the case.
Most of the major casinos today are enormous complexes and it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slots near any entrances.
Yet another classic rule is that loose slots are installed on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be influenced to play. Importantly however, 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 the slot machines 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 slots.