Books have been said on this topic, and the contention and disharmony about where the "hot" slot machines are installed in the casino are still on-going – more than sixty years after slot games were 1st placed in gambling dens.
The standard rule is that the more favourable one armed bandits were located just inside the entrance of the casino; so that potential players walking by would be able to see jackpot winners and be titillated to come inside … play. Our feeling is that this is no longer true.
Almost all of the big name casinos presently are grand complexes … it is not possible to see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ slot games near any entrances or exits.
An additional traditional rule is that loose one armed bandits are placed on the major aisles in the casinos, again so that more persons could see winning jackpots and be roused 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 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot machines.