You may have heard about private blog networks (PBNs) before, but you may not be sure what they are or why they are used. A PBN is a network of websites used to build links (and therefore pass authority) to a single website for the purpose of manipulating search engine rankings. This scheme is similar to a link wheel or link pyramid, as it involves several different websites all linking to one another or to one central website.
While these types of schemes were used commonly years ago, PBNs are now considered a pure black hat tactic and should be avoided at all costs, as they can lead to a loss in rankings, or even a manual penalty. PBNs usually provide little to no long-term value to the websites they are linking to.
Google has long been fighting PBNs, and businesses caught up in this shady tactic have been made an example of over the years. One such case was the J.C. Penney link scheme that was exposed back in 2011 by The New York Times. As Google gets smarter and develops better technology to combat link spam techniques, it has become harder and harder for black hat SEOs to pull off a PBN successfully.
[Read the full article on Search Engine Land.]