Private Blog Network
Right now the best links are from guest posts from the private blog network. The Private Blog Network (PBN) is a network of authoritative websites used to build links to your money website. One crucial part here is that each of the individual PBN sites is not linked to each other in any way. The idea of a private blog network is that the websites appear unrelated to each other, therefore natural links, as opposed to someone linking to their website from their other sites.