Clap, pause too long and it stops listening, clap again, clap louder — and even when The Clapper did register, it could fry whatever it was wired to. None of that stopped it from becoming one of the most memorable products of the 1980s. The Verge’s David Pierce and Victoria Song spend a full 70 minutes tracing it from its original pitch as The Great American Turn-On through one of the great infomercial campaigns, asking whether it was ever a good idea or just a very good ad.