Via People.com –
Gary Dahl, the man who became a millionaire by selling ordinary rocks, died on March 23 at the age of 78.
Dahl, an advertising copywriter, thought up the Pet Rock in 1975, after listening to friends complain about having to care for actual pets. The Pet Rock became an unlikely fad through Christmas that year. They sold for $4 each, and Dahl became a millionaire by the time the product was discontinued in February 1976.