Google Revises Link Scheme Definitions: Guest Posts, Press Releases, Advertorials Can Hurt Rankings

Google has updated its guidelines to warn webmasters against advertorials with links that pass PageRank. Also, heavily optimized anchor text used in press releases, guest posts, and article marketing can negatively impact a site's search rankings.

Source: http://feedproxy.google.com/~r/sewblog/~3/-FNYsG93WHI/Google-Revises-Link-Scheme-Definitions-Guest-Posts-Press-Releases-Advertorials-Can-Hurt-Rankings

more info here more info here more info here more info here more info here more info here more info here