I had someone tree mail me the question because they didn't feel comfortable bringing it up in public. The question is: what will we do if you can't find enough other seeds that interest you? What if 50 packets are requested of you, but you can only find a few that you want? Are you obligated to send all 50 even if you only get a couple back?
I don't really know the answer to this, except that first, you're of course not obligated to participate if you don't see anything you want.
How have other swaps, like the piggy swap, et al, handled this scenario in the past?