In 1975, Gary Dahl was joking with friends about how annoying pets are.

He said the perfect pet would be a rock, because it doesn’t eat, move, or cause problems.
Instead of leaving it as a joke, he turned it into a product called Pet Rock.
It was literally just a smooth stone in a small box with air holes, plus a funny instruction manual on how to “train” your rock.
People loved the joke and started buying them.
He sold about 1.5 million rocks in a few months for around $4 each, while the rocks cost only a few cents.
He became a millionaire from selling actual stones.
Be crazy. Be audacious. Be shameless. That's how money is made.
Happy Eid.