What Did The Inventor Of The Pet Rock Later Try To Sell Americans Bit By Bit?

In 1975, Californian advertising executive Gary Dahl hit it big when his goofy novelty gift, The Pet Rock, became a huge fad. Millions of the little rocks accompanied by instruction books flew off the shelf at $4 a pop. via Pocket http://www.howtogeek.com/trivia/what-did-the-inventor-of-the-pet-rock-later-try-to-sell-americans-bit-by-bit/