Books have been said on this issue, and the conflict and disharmony about where the "hot" slot games are positioned in a casino are still ongoing – over 60 yrs after the slot machines were first placed in gambling dens.
The quintessential rule is that the most favorable slots were put just inside the entrance of the casino; so that fun seekers going by would be able to see real jackpot winners and be aroused to come into the casino … play. Our inference is that this is definitely no longer the case.
Practically all of the mega casinos nowadays are herculean complexes … you can no longer see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot machines in close proximity to any entrances or exits.
Another traditional rule is that loose slot machine games are positioned on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be galvanized 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 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 slots.