Books have been written on this topic, and the debates and discourse about where the "hot" slot machine games are located in a casino are still intense – over sixty yrs after slot machines were first added to the gaming floor in gambling houses.
The traditional rule is that the most favorable one armed bandits were installed just inside the main entrance of the casino; so that folks passing by would be able to see actual jackpot winners and be enthralled to come inside … play. Our observation is that this is no longer the case.
Most of the large casinos today are oversized complexes … now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ slot machine games close to any entrances or exits.
Yet another standard 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 influenced to play. Notably however, 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 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!
These days, casinos are constantly changing their philosophy about where to place the loose one armed bandits.