Where do TV pilots go when they die?

Television networks commission about 100 pilot episodes for new shows each year. But as Aquaman fans found out this morning, only about a third of those series actually make it into the fall lineups.

So what happens to all those dead pilots? Forbes.com has the answer:

A handful of shows find new life after the networks reject them. Several years ago, CBS ordered up Ed, a quirky drama created by David Letterman's Worldwide Pants production company, but ended up passing on it and handing the show over to General Electric's NBC, where it ran for four seasons. A few others, like Ethel is an Elephant, about a photographer who lives with, um, an elephant, and Heat Vision and Jack, about a renegade astronaut and his talking motorcycle, have found audiences on the internet or on television shows that celebrate failed television shows.

But despite efforts on the parts of the networks that pay for the pilots and the studios that make them, pilot season remains an expensive exercise in futility: Lots of time, money and effort is spent creating entertainment no one will ever see.

How much money? According to Forbes, more than $300 million.

Maybe Aquaman will pull an Ed, and get picked up by another network -- or get a callback from The CW to serve as a midseason replacement. Hey, stranger things have happened.

Related: The Top 10 failed TV pilots