Search Innovation: Yahoo Backlinks Theory

I've long used Yahoo to look over the backlinks showing to our site and clients websites as many SEO's have done over the years. I've noticed over these last few months that no follow links show up our business backlink search results. I'd noticed years before that our website URL would show up as a backlink in Yahoo results even though the link was not an active link on the page. Now with no follow links showing up my guess is there is some sort of link power in no follow links and non-active links on the page. No testing done as of yet as this is just a theory of sorts. Two of the no follow links we have to our business site are from high authority websites and show up in our Yahoo backlink results. I've long wondered if identifying text on the page or text without an active link had something to do with the overall score of the link popularity of the web page. It is an interesting concept since links are a major focus, but any SEO knows text on the page matters when it comes to optimization. It certainly would change the concept of no follow and how little those links are worth in marketers eyes.