Picture a man placing a smooth stone in a tiny box and selling it as a pet. That man was Gary Dahl. He marketed Pet Rocks with a wink and a straight face. The result: more than 1.5 million units sold and Dahl became a multimillionaire.The product itself was plain—a simple stone. But the idea was theatrical. Packaging and playful presentation made buyers buy into the joke. Some analysts say the suc...More