I use spyglass in order to find backlinks. I noticed sites have a backlink on 1000's of different irrelevant content sites (just a small link in the footer). May there are only 3 links in the footer. Again, the link is irrelevant to the topic. If I scan 1 of these footer links. This link gets a high linkvalue out of it. These sites do only linkbuilding like that and get a good PR. How people get placed there, do they buy these links, if so where to the buy them? Sorry, my English is not that good. But I hope you guys understand what i mean.