A pilot is sort of that, actually. TV pilots are produced as one-offs (often independently financed) and then shopped around to networks as a way to obtain fun

A pilot is sort of that, actually. TV pilots are produced as one-offs (often independently financed) and then shopped around to networks as a way to obtain funding for a full season. So it's a small step from that to saying "We'll finance this show if you can produce a pilot on your own."