I don't mind so much if no feedback is left when I buy something. So yeah, I'm a good buyer, know what i want, pay fast, etc. It's when I sell something that I'm more attached to the feedback, as it's my track record as a seller. Every buyer who's dealt with me has always been satisfied, so why not take a minute of their time to say so? I always leave them feedback. I just consider it common courtesy. But I guess these days, like common sense, it's nowhere near as common as the name implies...