There might be things about SD I don't understand and you might be right about communicating but, to me, there are fundamental problems. I might not know the size of an item until I package it. I might want to charge £3 but upgrade to a more expensive service as an act of goodwill. I might want to buy my postage at my local post office, to give them my business. But I am prepared to investigate it further to see if I've misunderstood it, or can make it work better for me and the good people who buy what I sell.