The rating game

I've been buying on eBay for a long time. The seller of my last purchase said feedback would be left for me as a buyer after I left feedback on the item. This isn't the first time I've been told that by a seller and it annoys me. If I pay for the item, isn't that the sum total of my responsibilities as a buyer? What else could I be rated on? I was satisfied with the item I bought and I left positive feedback. It's been nearly a month since I won that auction and paid for the piece. Hey, lady, I'm still waiting on you to follow through.