In 1975, Gary Dahl’s name might not have been familiar to you. However, by the start of the following year, it’s likely you would have heard of his unique invention that had turned him into a pop-culture sensation.

Dahl owned a California advertising agency that specialized in radio and TV ads. Business had fallen off recently, and the disheartened 38-year-old was often searching for a clever and marketable idea to turn his fortunes around.

One night, he and some pals were drinking at their favorite hangout in Los Gatos, a town in the rapidly growing Silicon Valley. Dahl’s pals were complaining about all the hassles and expenses involved with their household pets. Dahl, however, smiled and joked that he didn’t have such problems because his pet was a rock. This comment was met with laughter and led to a few more drinks.

Back home, Gary began writing the Pet Rock Training Manual, a 36-page, chuckle-inspiring booklet filled with puns, jokes and illustrations of various rocks in inaction. He lightheartedly explained that Pet Rocks required no feeding, walking, bathing, grooming or vet visits. They were hypoallergenic and didn’t bark, bite or have accidents on the floor. They were good at obeying certain commands—like “stay” and “play dead”—but required some owner assistance with “fetch,” “come” and “roll over.” 

He designed a cardboard pet carrier with ventilation holes and a bed of straw or shredded paper. The rocks, smooth stones from a beach in Baja California, were sourced from a local sand and gravel company and cost one penny each. The cost of straw or shredded paper wasn’t much more. Dahl’s biggest expense was the cardboard carrier.

He convinced two friends to invest $10,000 each in his product, and Pet Rocks soon began appearing in Bay Area novelty stores and at gift shows. The concept quickly gained national attention, especially after Newsweek featured the absurd pretend pet in an illustrated article. Gary made two appearances on “The Tonight Show,” and an individual named Al Bolt even released a single titled “I’m in Love with My Pet Rock.”

By Christmas, daily sales of Pet Rocks reached 100,000 units. After the holidays, and with 1.5 million units sold, the craze faded as quickly as the Hula Hoop had. By then, Gary, who made a 95-cent profit on each $3.95 sale, had earned over $1 million. He rewarded each of his newly wealthy investors with a shiny new Mercedes and bought himself a mansion in Los Gatos, complete with his own Mercedes in the garage.

To many, Pet Rocks were seen as a fleeting “craze du jour,” highlighting the absurdity of consumer culture. To others, the success of the novelty was a testament to clever marketing. Regardless, Dahl’s product left a lasting mark on the toy industry and American popular culture.

Gary summed it up for People magazine: “You might say we packaged a sense of humor.” ■