Books have been stated on this issue, and the contention and arguments about where the "hot" slot games are positioned in a casino are still taking place – over 60 years after the slot machines were first placed in gambling houses.
The standard rule is that the superior slots were located just inside the main entryway of the casino; so that people going by would be able to see actual jackpot winners and be convinced to come inside … play. Our presumption is that this is definitely no longer so.
Almost all of the large casinos nowadays are monstrous complexes and it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slot machines near to any entrances or exits.
An additional traditional rule is that loose slots are installed on the major aisles inside the casinos, again so that more folks could see winning jackpots and be influenced to play. Importantly however, we find that this also isn’t 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!
Today, casinos are constantly changing their perspective about where to place the loose one armed bandits.