Just to be fair to Google, and I don't really care to be... the rater document also says (I am going to paraphrase, since I cannot claim to have a copy)
If you visually remove all spam elements (PPC ads and copied content) from a page, and nothing remains, that is a characteristic of a spam page.
In other words - Google is calling its own product (PPC ads) a big signal of spam. And yes, they do in fact call out Cj directly. As well as Amazon and eBay.
Google also states that when a user enters a search and the resulting page is a list of PPC ads, that is a strong sign of a spam website. Correct me if I am wrong, but isnt that a direct example of adsense link units or google custom search?
Like PPG states on her post as well, it only takes a bit of searching on Google itself to find a copy of, or snippets from the raters guide everyone is referring to.