Volumes have been written on this issue, and the debates and discourse about where the "hot" slot machine games are positioned in a casino are still ongoing – 60 years after the slots were first placed in gambling dens.
The standard rule is that the superior slot machines were put just inside the main entry of the casino; so that folks going by would be able to see real jackpot winners … be smitten to come unto the gambling floor … play. Our estimation is that this is not so anymore.
The majority of the major casinos nowadays are humongous complexes … it’s no longer possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machine games near any doorways.
An additional traditional rule is that loose slot machine games are installed on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be inspired to play. Interestingly though, 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 slot machine games 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 perspective about where to place the loose slot machine games.