Originally Posted by mjtaylor
but the fact still remains. PageRank will not pass through a link that has a nofollow attribute.
Google SaysSource: http://www.google.com/support/webmas...n&answer=96569In general, we don't follow them. This means that Google does not transfer PageRank or anchor text across these links. Essentially, using nofollow causes us to drop the target links from our overall graph of the web. However, the target pages may still appear in our index if other sites link to them without using nofollow, or if the URLs are submitted to Google in a Sitemap. Also, it's important to note that other search engines may handle nofollow in slightly different ways.
nofollow is not a barred exit to any spider. As has been stressed often in these discussions the SE's decide what to do with nofollow based on what is already in their respective index. A nofollow to an indexed page MAY even pass some juice, though we are given to the assumption that none will pass.
As time has progressed this attribute has evolved to be just as elusive as the algorithms themselves. What is clear, though, is that nofollow links ARE followed.
From Google, http://www.google.com/support/webmas...&answer=96569:
How does Google handle nofollowed links?
In general, we don't follow them. This means that Google does not transfer PageRank or anchor text across these links. Essentially, using nofollow causes us to drop the target links from our overall graph of the web. However, the target pages may still appear in our index if other sites link to them without using nofollow, or if the URLs are submitted to Google in a Sitemap. Also, it's important to note that other search engines may handle nofollow in slightly different ways.
What are Google's policies and some specific examples of nofollow usage?
Here are some cases in which you might want to consider using nofollow:
* Untrusted content: If you can't or don't want to vouch for the content of pages you link to from your site — for example, untrusted user comments or guestbook entries — you should nofollow those links. This can discourage spammers from targeting your site, and will help keep your site from inadvertently passing PageRank to bad neighborhoods on the web. In particular, comment spammers may decide not to target a specific content management system or blog service if they can see that untrusted links in that service are nofollowed. If you want to recognize and reward trustworthy contributors, you could decide to automatically or manually remove the nofollow attribute on links posted by members or users who have consistently made high-quality contributions over time.
Do not all the major SE's recognize this attribute?Originally Posted by mjtaylor
Source: http://www.google.com/support/webmas...n&answer=96569Also, it's important to note that other search engines may handle nofollow in slightly different ways.
So,Even Google is not sure, how this attribute is handled by other SEs. Here is a related post http://www.searchenginejournal.com/h...ttribute/4801/
From my experience a LINK is still a LINK. I use nofollow LINKS to increase my LINK count in yahoo. But my main strategy is building diversified dofollow anchor text LINKS.
Of course, Nofollow links helpful for getting position ahead in Search engine. Only Google does not crawl the nofollow links but other search engine such as Yahoo, Bing, MSN crawl the nofollow links. So in those search engines site position will increase.
From http://en.wikipedia.org/wiki/Nofollo...search_engines:In Bing's own community forum there is a note:While all engines that support the nofollow value exclude links that use it from their ranking calculation, the details about the exact interpretation of it vary from search engine to search engine.
* Google states that their engine takes "nofollow" literally and does not "follow" the link at all. However, experiments conducted by SEOs show conflicting results. These studies reveal that Google does follow the link, but does not index the linked-to page, unless it was in Google's index already for other reasons (such as other, non-nofollow links that point to the page).
* Yahoo! "follows it", but excludes it from their ranking calculation.
* Bing respects "nofollow" as regards not counting the link in their ranking, but it is not proven whether or not Bing follows the link.
* Ask.com also supports the attribute. 
All backlinks left in comments (including signatures) will be configured with the <a> tag attribute rel="nofollow", meaning that even if the backlink is retained in the post, there is no search engine backlink value attributed to the linked page from the Bing community. The function of the <a> tag's rel="nofollow" attribute applies to all search engines that crawl the Bing community blogs and forums, not just the Bing crawler.
Also from the wiki page, http://en.wikipedia.org/wiki/Nofollo..._specification:
The concept for the specification of the attribute value nofollow was designed by Google’s head of webspam team Matt Cutts and Jason Shellen from Blogger.com in 2005.
The nofollow value was originally suggested to stop comment spam on blogs. Believing that comment spam affected the entire blogging community, in early 2005 Google’s Matt Cutts and blogger’s Jason Shellen proposed the value to address the problem.