Interesting debate, of which I can see both sides. While I used to immediately leave positive feedback upon payment receipt, as a seller, I've been burned innumerable times by buyers making false claims about items not being delivered (when shipping tracking indicates otherwise), not working, new ones having been opened and used upon receipt, etc. I can't count how many, mainly International buyers, have tried to scam me out of both payment and item by making such false claims. Then when I fight the ebay cases opened against me, which I win but devote time to rectifying, some buyers have gotten pissed and left me negative feedback, to which I have to devote additional time to have removed by ebay. So the dishonest buyers have ruined the process now for all, since I'll be damned if I'm going to leave positive feedback only for them to try and scam me out of both my money and item, and then also leave me negative feedback. Now, regardless of how pleasant the transaction was initially, no buyer feedback is left until I receive appropriate feedback, positive or negative, of my own.