Books have been said on this subject, and the contention and disagreement about where the "hot" video slots are installed in a casino are still taking place – more than 60 yrs after slot machines were first placed in gambling dens.
The classic rule is that the better one armed bandits were installed just inside the main foyer of the casino; so that potential gamblers going by would see actual jackpot winners and be intrigued enough to come unto the gambling floor and play. Our feeling is that this is no longer the case.
Practically all of the large casinos nowadays are herculean complexes and it is not possible to see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot games near any exits.
An additional classic rule is that loose slot games are located on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be motivated to play. Importantly 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 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!
Nowadays, casinos are constantly changing their philosophy about where to place the loose slot machines.