Volumes have been stated on this matter, and the debates and discussion about where the "hot" one armed bandits are positioned in a casino are still there – more than 60 years after one armed bandits were 1st added to the gaming floor in the casinos.
The quintessential rule is that the most favorable slot machines were located just inside the main doorway of the casino; so that potential players walking by would be able to see actual jackpot winners … be challenged to come inside … play. Our reckoning is that this is not so anymore.
The majority of the large casinos nowadays are magnificent complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot machine games near to any of the doors.
Another classic rule is that loose slots are put on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be energized 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!
These days, casinos are constantly changing their perspective about where to place the loose slot games.