Books have been stated on this subject, and the conflict and arguments about where the "hot" slot games are positioned in a casino are still on-going – over sixty years after slot games were 1st placed in casinos.
The quintessential rule is that the very best slot machines were placed just inside the entry of the casino; so that folks passing by would be able to see jackpot winners … be drawn to come inside and play. Our inclination is that this is no longer true.
The majority of the big name casinos presently are herculean complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot games in close proximity to any entrances.
Yet another standard rule is that loose slot games are located on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be galvanized to play. Notably though, 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 the slot machines 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.