eBay is a community that encourages open and honest communication among all its members. Our community is guided by five fundamental values:

We believe people are basically good.
We believe everyone has something to contribute.
We believe that an honest, open environment can bring out the best in people.
We recognise and respect everyone as a unique individual.
We encourage you to treat others the way you want to be treated.

eBay is firmly committed to these principles. And we believe that community members should also honour them—whether buying, selling, or chatting with eBay friends.

Feedback:

Feedback is made up of comments and ratings left by other eBay members you’ve bought from and sold to. These comments and ratings are valuable indicators of your reputation as a buyer or seller on eBay. They are included, along with an overall feedback score, in your Member Profile.

Always leave feedback after a transaction so that other members may benefit from your experience.
Usually, a high feedback score and high positive feedback percentage is a good sign, but you should always check your seller/buyer’s Member Profile for negative remarks.
Keep your Member Profile public–buyers may be wary of trading with someone with a private Member Profile.
Contact the seller/buyer to resolve any issues before leaving negative feedback.
You cannot remove feedback you’ve left, unless you both agree to withdraw. So be sure to make only fair and factual comments and give ratings that relate to a specific transaction