There are many reasons products become popular. Sometimes it's simply because it's the coolest new gadget or brand. But sometimes it's because it solves a problem (perhaps a problem people didn't even know they had). Problems, big or small, matter to people. As a result we have not only seen a craze in lifehacks but also innovative solution based products.
I recently read about two such product innovations. The first, solved a rather "small" problem, the subconscious shame some women feel because they wear their hair elastic around their wrist.