Create a live feed of your eBay feedback to display on your site.
Create a nice table of your feedback score and show everyone what type of feedback you have received, left for others, received as a buyer or as a seller. Your showing of your feedback can speak a lot to your users who view it.
Have them trust you: All visitors like to see how good your feedback is. With this, you can convince your visitors how good you are of a business person and in return, turning them into potential costumers.