Google has reportedly handed out penalties to sites using PBNs, penalizing them for “thin” content. What is a PBN? PBN stands for private blog network. Private blog networks are a group of blogs or websites that are all controlled by one publisher. The name is a little misleading because they aren’t actually private. People can see them but they aren’t actually meant for the public.
Public blog networks are used for SEO purposes. Because all the blogs or sites are controlled by one publisher, they can use it to their advantage by building up a network of backlinks to help their pages rank better in search results.
Under Google’s webmaster guidelines, thin content is considered search spam, which is why PBN sites will be given these penalties.
Those that run PBNs are not convinced that this means the end for them because in theory, high quality PBNs with strong content could survive but it is clear that Google is not a big fan of them.