I made a couple sales 2 weeks ago directly from co-op links. Checking the stats there was a corresponding spike in impressions; about 4,000. This is probably a more common experience to those with more weight. In this case I could see the only page visits those days were from co-op referrals. (I checked the referrers and they were showing co-op ads) The ad was a simple one word product name, linking to that product page. There is also a boost to that pages toolbar pagerank of 4. While that domains index is a mere 2! The index page is a poorly planned mall that has no keyword focus. (I'm learning!) There was also a temporary jump in google serps for that page to the top 10. The product name keyword is in the co-op anchor text, the URL, Title, description, Headline, and page text once with emphasis and combined in different phrases. I'm sure this is no news to the experienced. But it is another cathartic moment for me. When after taking all the seo advice on blind faith for months I finally see hard evidence of it working. Believing is nice, but knowing is so much better! Basically I'm saying there was in this case a direct correlation between co-op impressions and page rank, plus I received converting traffic! Have I said "Thanks Shawn!" yet? Thanks to Shawn and all the other help here!