As already mentioned of penalties on UK Newspapers which caused their Page Rank (Some of these even goggle to zero PR) and search engine rankings drop on large scale. Its also confirmed that Google also sending notification to these link selling sites and some of those confirmed as well.
Matt Cutts clearly stated the downfalls of selling links
“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. The consequences for a linkselling site start with losing trust in Google’s search results, as well as reduction of the site’s visible PageRank in the Google Toolbar. The consequences can also include lower rankings for that site in Google’s search results.”Google further advices for those who received such email notifications in webmaster tools to remove those paid links or use rel=”nofollow” attribute. You need to submit reconsideration request after removing all the paid links. Its also possible that in an extreme case, site selling links can be fully removed from Google’s search results.