Books have been written on this matter, and the debates and interchanges about where the "hot" slot machines are placed in the casino are still happening – more than sixty yrs after the slots were first added to the gaming floor in gambling dens.
The standard rule is that the more favourable one armed bandits were placed just inside the main entrance of the casino; so that people passing by would see actual jackpot winners and be stirred to come into the casino … play. Our point of view is that this is definitely no longer true.
Almost all of the major casinos today are mammoth complexes and now you can’t see inside from the sidewalk, so there’s no longer a reason to have the ‘loose’ slot machines near to any entrances or exits.
An additional standard rule is that loose one armed bandits are installed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be influenced to play. Interestingly 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 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!
In recent times, casinos are constantly changing their philosophy about where to place the loose slot machine games.