Is anyone old enough to have used FindWhat, at the time it was a CPC engine? As a publisher I used them, before joining Adsense. It was really great. This was the early age of ad networks for all kind of publishers. They paid well, and I even received a mug when I joined, it's certainly collector now :)
What was great, but certainly over abused, and never to be seen again, is that, you were retrieving yourself advertisers. This required server side PHP programming (certainly available in other language too). You were sending a request to the FindWhat server, with keywords, and it was returning an XML file, with the list of advertisers, image and URL codes and how much was the CPC ! So, you were able to filter which ad to show. Of course, this was certainly abused, because you could query any keywords.
