This article is from the eBay FAQ, by William B. Shaw firstname.lastname@example.org with numerous contributions by others.
EBay's feedback system is only effective if all members leave deserved
feedback for both good and bad transactions. Many buyers and sellers are
hesitant to leave negative feedback for fear of retaliation. I can state
from personal experience that this fear is for the most part unfounded. Out
of the first 77 negative feedbacks I left for other members in my eBay
career, not one resulted in a retaliatory negative on my record.
With that said, I would caution that retaliatory feedback does exist and I
do expect to receive one at some point. If you do receive a retaliatory
feedback, the best solution is to respond to it in a professional and matter
of fact manner. The response speaks louder than the negative and can show
potential trading partners where the fault actually lies. If your feedback
is otherwise sound, very few people will concern themselves with isolated
One way to potentially protect yourself against retaliatory feedback from
buyers is by proactively contacting other sellers who haven't left feedback
and asking how the transaction went. Often, if they also had a bad
experience, they will follow your lead and leave the negative feedback and
claim their FVF refund (three of which NARU's the buyer and prevents them
from leaving any feedback.