A deed owner can decide if they want to sell adverts on their deed, and how much they want for them. If you want to advertise on someones deed simply find the deed that you want and see if adverts are available. If they are, then click on the link that will take to to the advert submission page.
You can submit a link with 150 character description. Once paid for, the deed owner simply places your advert on their deed. Once they do so your advert is locked in place on their deed for 3 months. This is a security measure so that your advert cannot be tampered within in any way.