Hi Denis, thanks for asking about this. That message typically indicates that we believe a site is selling links that pass PageRank, which is a violation of our quality guidelines. See  and  for more info on our policies. As rustybrick and http://techcrunch.com/2011/02/16/forbes-accused-of-link-spam-plays-dumb-but-forgets-to-delete-all-the-links/ point out, the links at forbes.com/ebusiness/ are a specific instance that violate our guidelines. People on this thread have already mentioned Conductor, and I've confirmed multiple times that paid links that pass PageRank via Conductor violate our guidelines. See  for those confirmations.
My recommendation would be that Forbes remove the paid links that pass PageRank. I should mention that I believe we have another example of paid links that pass PageRank on Forbes which is similar to forbes.com/ebusiness/ , so it probably makes sense to do a full check of your site for any links similar to that or powered by the same network. After the links are gone, you can submit a reconsideration request  and we'll move forward from there.
 I've commented on an article about Conductor as long ago as 2008 at http://www.businessinsider.com/companies/linkexperts#comment-7c7a6c797dc19948b3d4d400 when it was still called LinkExperts. At the time I said "As the head of Google's webspam team, I would just like to point out that paid links that pass PageRank are absolutely a violation of Google's quality guidelines, and we do take action on those violations." I also commented on Twitter just a few months ago at http://twitter.com/#!/mattcutts/status/22019997220 when I said "Because someone asked me about it: Conductor paid link network does violate Google's quality guidelines, and we do take action in response."