If I want to solely promote eBay through social media, do I still have to register my domain?
Yes, you will still have to register at least one domain when you sign up for ePN, regardless of how you are planning to drive traffic to eBay. If it is via social media, please note that you must register the full URL. So, if John Smith wants to use Facebook to promote baseball cards, he should register either his personal profile – www.facebook.com/johnsmith - or his Facebook Page - www.facebook.com/baseballcards.