I had sold a book via amazon. The client never got the book. I know that I've sent it. I offered that in case that the book wouldn't arrive I'd pay back the expenses. The client wrote me today that the book didn't arrive, but that I can keep the money. We speak about 8 Euro. Nevertheless, this is such a friendly gesture. I wrote her that I want to make her a book present and she should wrote me what would please her. She could give me a bad mark at amazon.
Such stories make me feel good. Really. Friendliness is contagious.