I have encountered the same issue- my sales went up but profit declined.
I started by using half of eBays recommended percentage of promotion- if
they said 8%, I used 4%. My listings still sold at about the same rate-
and still higher than non-promot...
You should be able to reply to the negative feedback- but don't be
defensive. State the facts- buyer claimed product was defective and was
promptly sent a return label. Buyer never returned item. Short and
sweet, you have addressed the main issue. Go...