I think the idea is that you would have a discussion, and at the point where you're like "ok, this deal is set, I'll ship on Tuesday" you open a formal trade request to the user. They accept it and the terms, and then you both ship. If someone doesn't accept the trade request, then the idea is that the other person decides not to ship. Obviously if you decide to not use it, then you're not using it. That's fine. I know that as long as it is a smooth process, I'd likely politely insist on using it, and the hope is the majority of the traders would also. Why not?