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Pet Rocks (1975)

Manufacturer: Rock Bottom Productions

Like many toy fads, it is the marketing that makes all the difference. Pet Rocks were sold in cardboard boxes, punched with air holes, and accompanied by a 32-page training manual.

The craze ended almost as abruptly as it started, but over the span of six months, more than 5 million were sold. Sales peaked during Christmas 1976, but by February the toys were in the discount bin. Still, the fad lasted long enough to make Gary Dahl, a California advertising executive, into a multimillionaire.

The Pet Rock was first shown at a San Francisco gift show, and Neiman Marcus was one of the first retailers to sell it. Shortly after, it became a media sensation, with articles in newspapers and magazines. Dahl even appeared on "The Tonight Show" twice to talk about his creation.

Photo: That70sShoppe | Etsy.com