Books have been stated on this topic, and the disquiet and arguments about where the "hot" slot games are located in the casino are still rampant – sixty yrs after slot machine games were 1st added to the gaming floor in gambling houses.
The classic rule is that the better slot machine games were installed just inside the main foyer of the casino; so that potential gamblers going by would see jackpot winners and be inspired to come unto the gaming floor and play. Our theorem is that this is not so anymore.
Almost all of the mega casinos presently are colossal complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ one armed bandits near to any doors.
Another traditional rule is that loose slot games are positioned on the major aisles inside the casinos, again so that more people could see winning jackpots and be motivated to play. Nonetheless, we find that this also is not 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 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!
Nowadays, casinos are constantly changing their perspective about where to place the loose slot machines.