Books have been written on this item, and the conflict and feuds about where the "hot" slot machines are located in the casino are still rampant – over sixty yrs after slot machine games were 1st placed in gambling houses.
The traditional rule is that the better slot machines were located just inside the main entrance of the casino; so that potential players going by would see actual jackpot winners and be mesmerized enough to come unto the gambling floor … play. Our inclination is that this is definitely no longer the case.
The great majority of the mega casinos presently are super-colossal complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ slots close-by any entrances.
Another traditional rule is that loose slot machines are positioned on the major aisles inside the casinos, again so that more folks could see winning jackpots and be energized 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 slots 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!
Today, casinos are constantly changing their perspective about where to place the loose slots.