What year was the pet rock released?

The answer is: 1975

Gary Dahl had heard enough bar complaints about needy pets to last a lifetime. So one night, the advertising copywriter joked that he had the perfect pet - a rock. It needed no feeding, no walking, no grooming. It was always house trained. And unlike most bar-born bright ideas, this one actually worked.

Dahl launched the Pet Rock in August 1975, just in time for holiday shopping. He'd spent months perfecting every absurd detail: cardboard boxes with air holes, beds of wood shavings, and a deadpan 32-page training manual. The manual advised owners that while Pet Rocks learned "stay" quite easily, "roll over" might require a gentle nudge.

By Christmas, stores couldn't keep them on shelves. His simple pebbles from Mexico's Rosarito Beach, purchased for pennies each, sold for $3.95 - about $20 in today's money. Each rock came with an unspoken invitation to play along with the joke.

Office workers displayed them on desks. Kids brought them to show and tell. Critics called it the ultimate symbol of consumer foolishness, but that was exactly the point. The Pet Rock never pretended to be anything more than what it was: a perfectly ordinary rock in a funny box with a silly manual.

Some estimate Dahl eventually made around $15 million from his invention. The fad faded fast, but for one brilliant moment, the dumbest idea in retail history had worked exactly because it was the dumbest idea in retail history.