when you sign up to ebay it is assigned to you and adsense will work as long as your account is not deactivated just enter your pub number located in the top right hand corner of your adsense dash board when you first log in. As for ebay I am not really sure where to find it because I don't use ebay because it takes far too long to earn a good income with them and to post or sell something on ebay they do charge you. I hope I have answered your question. Thanks for asking and Keep reading. Also check out my articles they might help with any future questions you might have. I will be writing a few more this week so check back often thank you.