Hi Im new to this forum. Google checks backlink diversity. This term refers to the overall view of your backlinks and considers a wide range of link attributes including the linking page types, content types, domain names, IP address, anchor usage, PR, degree of relevancy, follow/nofollow, and more. linking page type is only one of these factors, so you can easily meet all the others. If you think about it, articles, blogs, directory, and social bookmarking are all a similar niche. They are all user posted information websites. Basically all just websites that are controlled by users and moderators. Google probably picks up a similar / same type of website between blogs and social bookmarking, and most likely picks up the same for articles and directories (also pretty much the same thing for everything except length. Do you think just blogs and directories will do the job? They are the only/best 2 types of backlinks that will provide you with a high pr backlinks. Whats your input on this? I know most big companies use mostly blogs.