The Porn Gnome theory usually works, but bush porn are like holy scrolls, or hole-y scrolls, whatever works. As such, they get passed down from generation to generation, from parent/older brother/skeezy guy who bought it in exchange for them also buying him a six-pack, to high schooler, and from high-schooler to junior high schooler, and from junior high to elementary, always left in a bush waiting for the next person to be deemed worthy of the scroll's power, like Excalibur's sword in the stone. It's a very spiritual passage.

Likewise, the modern day lack also is killed by this, as the original holy scroll seekers soon found the local free alt-weekly newspaper is free, no one will question a person grabbing a copy, and their need for low-quality grot and complete lack of standards means that to them, the phone sex adverts in the back is the same quality grot and gives them the same benefit.