Books have been written on this subject, and the conflict and discourse about where the "hot" slot games are installed in a casino are still bubbling – over sixty yrs after slot machine games were 1st placed in gambling dens.
The standard rule is that the very best slot games were placed just inside the main foyer of the casino; so that casino fanatics walking by would see jackpot winners … be baited to come unto the gaming floor … play. Our theory is that this is definitely no longer true.
Most of the major casinos these days are colossal complexes … it is not possible to see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ one armed bandits near to any doors.
Yet another traditional rule is that loose one armed bandits are located on the major aisles inside the casinos, again so that more folks could see winning jackpots and be roused 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!
These days, casinos are constantly changing their perspective about where to place the loose slots.