Sellers can send a feedback revision request if a buyer's concern is resolved.

Many high-volume sellers use automated systems to leave positive feedback immediately upon payment. By making quick payments on multiple cheap auctions, a user can gain 50–100 feedback points for approximately $15–$20. The Risks of "Feedback Manipulation"

Violations can lead to account suspension, restricted buying/selling privileges, and the removal of the manipulated feedback or listings. Alternative Reputation Management