Andy_Langton - 11:40 pm on Feb 22, 2013 (gmt 0)
There appears to be a follow-up directly from Google on this:
A reminder about selling links that pass PageRank
Please be wary if someone approaches you and wants to pay you for links or "advertorial" pages on your site that pass PageRank. Selling links (or entire advertorial pages with embedded links) that pass PageRank violates our quality guidelines, and Google does take action on such violations.