Sleep trackers have become increasingly popular, but for some people, perfecting their sleep score becomes an end unto itself, reports NPR.

A third of Americans say they don’t get the recommended seven hours of sleep a night, according to the Centers for Disease Control and Prevention.

That’s fueling a boom in products promising to help people improve their sleep.

The sleep market is worth tens of billions of dollars, from weighted blankets to tech gadgets like trackers and meditation headbands.

Get the full story at npr.org