Books have been said on this issue, and the disquiet and discord about where the "hot" slot machine games are positioned in the casino are still there – more than sixty years after slot machine games were 1st placed in gambling dens.
The quintessential rule is that the most favorable slot machines were installed just inside the entry of the casino; so that everyone passing by would see actual jackpot winners and be drawn to come into the casino … play. Our presumption is that this is not so anymore.
The great majority of the mega casinos presently are grand complexes and you can no longer see inside from the sidewalk, so there is no longer a reason to position the ‘loose’ slot machine games near to any entrances or exits.
An additional traditional rule is that loose slot games are placed on the major aisles inside the casinos, again so that more potential gamblers could see winning jackpots and be influenced 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 one armed bandits 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!
Today, casinos are constantly changing their philosophy about where to place the loose slot machine games.