Books have been written on this topic, and the bickering and face-offs about where the "hot" slots are placed in the casino are still happening – over 60 yrs after slot machine games were 1st placed in gambling houses.
The quintessential rule is that the best slots were positioned just inside the main entryway of the casino; so that persons going by would see real jackpot winners … be attracted to come unto the gaming floor … play. Our finding is that this is no longer true.
Most of the mega casinos presently are humongous complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to position the ‘loose’ one armed bandits near to any exits.
Another traditional rule is that loose slot machines are placed on the major aisles in the casinos, again so that more persons could see winning jackpots and be encouraged 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.