Books have been stated on this topic, and the bickering and discord about where the "hot" slot machines are placed in a casino are still raging – more than sixty years after slot games were first placed in the casinos.
The standard rule is that the most favorable slot machines were installed just inside the entry of the casino; so that everyone passing by would be able to see jackpot winners and be aroused to come unto the gambling floor … play. Our viewpoint is that this is not so anymore.
Most of the mega casinos presently are titanic complexes … you can no longer see inside from the sidewalk, so there is no longer a reason to situate the ‘loose’ slot machines in close proximity to any entrances.
An additional standard rule is that loose one armed bandits are put on the major aisles in the casinos, again so that more potential gamblers could see winning jackpots and be inspired to play. Notably though, 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 the 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 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 slots.