Books have been said on this subject, and the contention and interchanges about where the "hot" slot games are positioned in the casino are still there – over 60 yrs after the slot machines were first installed in gambling houses.
The quintessential rule is that the most favorable slots were located just inside the main foyer of the casino; so that persons passing by would be able to see actual jackpot winners … be challenged to come unto the gaming floor … play. Our inference is that this is definitely no longer true.
Nearly all of the major casinos nowadays are herculean complexes … it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ slot games near any doorways.
An additional traditional rule is that loose slot machine games are placed on the major aisles in the casinos, again so that more people could see winning jackpots and be motivated to play. Importantly however, we find that this also is no longer a universal rule.
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!
Today, casinos are constantly changing their philosophy about where to place the loose slot machines.