You need to be an "Above Standard" or "Top Rated" seller to use Promoted Listings.
You have a brand new account eBay requires a certain level of recent selling activity to ensure sellers are in good standing, this ensures that sellers are reliable and committed to fulfilling orders, making it worthwhile for eBay to promote their listings.
You need to make some successful sales and gain an Above Standard or Top Rates seller status, to be able to promote your listings.
