This was a 24-hour coding challenge project I did in 2011, before I went away to college. Its purpose was to let users accumulate points by visiting referral links to other sites. After enough points, they could add their own ads linking to their referral sites.
It was a very basic site with no user accounts, written in PHP, and it got several million page hits at its peak. I’ve since sold the domain to someone else, who has launched their own iteration of the site.