Ebay feedback blackmail

If you do business on Ebay, whether you are power seller with your own store there or simply a John Doe such as myself, please follow the following etiquette:

• If you are selling, and the item(s) you sold get paid (right away or in a timely manner), leave your feedback right away. No need to wait till the buyer leaves his. Doing so is bad, really bad.
• If you are buying, wait till the item arrives and then leave a feedback accordingly. Consider communication with the seller, quality of item as advertised, etc.