Using the "Feedback Score" to evaluate a member. 

There are two parts to the feedback score you need to pay attention to. The first one you usually see is the number in parentheses just to the right of the seller id. This could be zero or any number greater than zero and it tells you the number of feedback entries that seller/buyer has received. I higher number indicates more feedback received meaning that ebay member has bought and/or sold more items on eBay and has more experience with the eBay system. High numbers don't necessarily mean good things about the buyer and a low number doesn't indicate something bad.

The second part is the "Feedback Percentage" which indicates the number of positive feedback results that member has received. 100% is the best feedback percentage you can obtain. The lower the feedback percentage the fewer positive results the member has received and this usually indicates a problem with the member. I try not to do business with members that have less than a 100% feedback rating. This is easy to do as a buyer. You simply don't bid on items listed by sellers with less than a 100% rating. If you don't want to deal with buyers with low feedback percentages you must be specific in you item listing. You can state, in your item listing, you do not accept bids from members with less than a 100% rating. This may help avoid deadbeat bidders.

While you are looking at the feedback score you also need to consider how long the member has been on eBay and how long they have had the same user id. The longer they have been a member and the longer they have used the same ID the better they generally are. {more on evaluating buyers and sellers]