Books have been stated on this item, and the bickering and interchanges about where the "hot" one armed bandits are installed in a casino are still happening – over sixty yrs after slot machines were first installed in the casinos.
The quintessential rule is that the more favourable slots were installed just inside the main entrance of the casino; so that people walking by would see jackpot winners and be attracted to come unto the gambling floor and play. Our inference is that this is not so anymore.
Almost all of the big name casinos presently are huge complexes and it is not possible to see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slots close to any doors.
Yet another traditional rule is that loose slot games are placed on the major aisles in the casinos, again so that more fun seekers could see winning jackpots and be inspired to play. Notably 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 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 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.