This article is from the eBay FAQ, by William B. Shaw firstname.lastname@example.org with numerous contributions by others.
Incendiary topic #1!! Opinions vary greatly. Many sellers don't consider the
auction to be complete until the buyer acknowledges receipt of the item and
states that everything is in order. Other sellers feel that once a buyer has
paid, they have fulfilled their obligations and feedback is in order.
Whatever your decision, stick with it and don't keep it a secret. Post your
feedback policy on your 'About Me' page so that buyer's can know what to
Keep in mind that many buyers consider themselves 'feedback hostages' when
sellers employ the strategy of leaving feedback only after the other party
has done so. Good sellers generally only receive feedback on about 50-60% of
their sold auctions. Many buyers will react strongly if they feel pushed and
an otherwise smooth transaction can end up with poor results for the seller.