Books have been written on this matter, and the bickering and interchanges about where the "hot" slot machines are located in the casino are still rampant – sixty years after slot machine games were 1st installed in the casinos.
The traditional rule is that the more favourable slot machines were installed just inside the main entrance of the casino; so that fun seekers walking by would be able to see actual jackpot winners … be captivated to come unto the gambling floor and play. Our sneaking suspicion is that this is definitely no longer so.
The great majority of the mega casinos these days are humongous complexes … you no longer can see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slot games near any of the doors.
Yet another standard rule is that loose slot machines are placed on the major aisles in the casinos, again so that more people could see winning jackpots and be energized 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 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 philosophy about where to place the loose one armed bandits.