I found on DP or other forums hundreds of offer for Building Backlinks. Some are quit cheap. Other sell ebook who promise you tones of backlinks and great PR or SERP. But when I cheeking the sites (from profiles), I found that all sites have no more than PR2. I was thinking until now that somebody who can rise your site, can easily rise his own site easily. How somebody who can't manage even his own site's can help you to build strong sites? It's world of SEO full of "fraud"?
typo: "Cheeking" - "checking" SEO is real but some seemed to destroy SEO's credibility. Low Trafficked Websites promoting SEO is a "fraud" or maybe promotes unreliable resources or information. So just believe in SEO experts who owns websites with high traffic such as SEOMoz, MattCutts and Aaron Wall's SEOBook.
I don't think MattCutts is "promoting" SEO or linkbuilding services like SEOMoz or SEObook. He's a Google employee and the only "promotion" he's doing is getting the word out re SEO standards (from Google's perspective).
Matt Cutts is the owner of seobook.com. If you look at a couple of his videos where he uses his site as an example you can make out the seobook .com logo.