Books have been stated on this topic, and the conflict and squabbling about where the "hot" slots are placed in the casino are still taking place – more than 60 years after the slot machines were first placed in casinos.
The traditional rule is that the best slots were installed just inside the main foyer of the casino; so that people walking by would see actual jackpot winners … be tempted to come inside and play. Our resolve is that this is definitely no longer the case.
Nearly all of the major casinos these days are huge complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot games near to any doors.
Another classic rule is that loose slot games are placed on the major aisles in the casinos, again so that more potential players could see winning jackpots and be encouraged to play. Notably however, we find that this also isn’t 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 slots 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 perspective about where to place the loose slot machines.