Reservations about Reservations in USFS campgrounds

First time I encountered it was the Environmental Campsites, now called Steep Ravine, ocean front walk in sites just north of San Francisco. The sites were only $2 a night if I remember right in 2000. They were pretty much impossible to get and almost full of no shows when we were there. I blamed it on both popularity and too low a price. Got to make it hurt a little so folks cancel when they're not going to show up.