Should I Build Dofollow or Nofollow links?
It doesn't matter what type of backlinks you build. Both types pass link juice, and it's good to have a mix. Google takes into account both types and gives extra credit, of course, to dofollow links. You don't want to forget, though, that nofollow links are still a great source of referral traffic. You can find nofollow links everywhere: in blog comments, sidebar links, footer links, forum profiles and signature links, social bookmarks. Google suggests webmasters add the nofollow tag to all paid links.