Click the link above to go to the page with the ptcs. The more ptcs folks purchase the more will be on the wall :).
This is a great way to get a lot of your referral links out there for folks to see all sorts of different sites. As a referrer myself, I love this type of wall, and as the popularity grows, so will the amount of ptcs available, and thus the earning potential for everyone.
Here is the link to purchase ptc advertising :)