Books have been said on this subject, and the conflict and disagreement about where the "hot" slots are located in a casino are still ongoing – more than 60 years after the slot machines were 1st installed in gambling houses.
The traditional rule is that the most favorable slots were placed just inside the entry of the casino; so that folks walking by would be able to see actual jackpot winners and be tempted to come into the casino … play. Our sneaking suspicion is that this is definitely no longer the case.
Nearly all of the big name casinos nowadays are magnificent complexes … you no longer can see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ slot machine games near any doors.
An additional traditional rule is that loose slots are positioned on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Interestingly though, 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 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!
These days, casinos are constantly changing their philosophy about where to place the loose slots.