Performancing ads is a new way to make money on the internet. You can either attract bloggers or publishers through them. You then get a share of the money the advertisers spend.
Perfomancing works with the 125x125 ads and reminds me a bit of Projectwonderful since they work almost in the same way. But different.
Check them out
here
You can see them in the right sidebar of this blog at the moment.