William Castle, King of B-movies, loved gimmicks. Giving audience members a certificate for a one-thousand-dollar life insurance policy in case Macabre caused them to die of fright. Red/blue glasses so you could see or hide the ghosts in 13 Ghosts. A forty-five-second “fright break” to leave and get a refund if you were too scared to watch the rest of Homicidal.
I wrote about The Tingler for Unwinnable! You can read it here.