Books have been written on this issue, and the conflict and interchanges about where the "hot" slot machines are located in a casino are still on-going – sixty yrs after the slot machines were first added to the gaming floor in casinos.
The standard rule is that the more favourable slots were placed just inside the entry of the casino; so that fun seekers going by would see actual jackpot winners … be titillated to come into the casino … play. Our frame of mind is that this is not so anymore.
Just about all of the mega casinos presently are grand complexes and you no longer can see inside from the sidewalk, so there’s no longer a reason to situate the ‘loose’ slots in close proximity to any exits.
Another classic rule is that loose slot games are installed on the major aisles in the casinos, again so that more potential players could see winning jackpots and be motivated to play. Notably though, we find that this also is no longer a universal rule.
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 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 philosophy about where to place the loose slot games.