Books have been said on this matter, and the debates and discussion about where the "hot" slot games are positioned in a casino are still there – sixty years after slot machine games were 1st placed in the casinos.
The standard rule is that the superior slot machines were positioned just inside the main foyer of the casino; so that everyone going by would see real jackpot winners and be enthralled to come into the casino and play. Our point of view is that this is no longer the case.
Many of the mega casinos presently are magnificent complexes and you no longer can see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ one armed bandits near to any entrances.
An additional classic rule is that loose slots are positioned on the major aisles in the casinos, again so that more persons could see winning jackpots and be motivated 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose slots.