6. You Could Call The Phone Number From The First Film...
To keep up the momentum of the slow-burn word-of-mouth success of the first film, director Ivan Reitman elected to have a new trailer run that was (essentially) just the first TV advert the Ghostbusters themselves make, only with the 555 number swapped out for an actual 1-800 number. If you rang it you got a recorded message of Bill Murray and Dan Aykroyd apologising that they were out busting ghosts. The number got something like 1000 calls per hour, 24 hours a day, for six weeks. The number in the film, meanwhile, is a "fictitious number" originating from early Bell Telephone ad illustrations.