I'd actually never heard of until it was mentioned on another QJ forum. And frankly, it's not something that would have ever ocurred to me.

There have been times when our group has stopped earlier than we maybe planned, because of what we thought would be limited campsites ahead. It's a choice you make. Either stop, or move on and take your chances. I would never think that tossing a pack down and keep looking for another site was even an option.

If you're travelling in a group of six and have twelve packs with you, you could leave quite a string of packs on various sites until you find the "perfect" one. That's just not right.