Archive for June 2nd, 2009

Nofollow Link Changes

Tuesday, June 2nd, 2009

When Google was first launched, it provided very relevant search results and quickly became a leading search engine. It was able to provide such relevant results largely because it paid a lot of attention of how websites linked to each other, and considered a link to a site to be equivalent to a vote for that site. The more “votes” a site had, the more popular it was perceived to be by Google, and the more likely it was to rank highly in Google’s listings.

After some time, Google introduced a nofollow attribute for a link, which ensures that, no benefit is passed. This is useful for blog pages or any situation where a link is useful but where site A cannot vouch for the credibility of site B. However, nofollow links have also been used for an SEO technique known as “link sculpting”.

In simple terms, when one page links to another, it passes a certain amount of PageRank to that page. If the page links to several other pages, the PageRank is shared among the links. However, nofollow links could be used to stop PageRank being passed to some pages, giving a greater share to those without the nofollow attribute. For example, if my index page links to five sub pages, each page receives a 20% share of the PageRank that is passed. This is of little benefit to my about us and contact us pages, so I decide to put the nofollow attribute on the links to these two pages. Now the remaining 3 pages have a 33% share, which may ultimately boost their credibility and position in the search engines.

In the past, this has had a beneficial effect for some websites. However, nofollow links are now handled in a different way by Google, and link sculpting is likely to do more harm than good. When a nofollow attribute is applied to a link, there will still be no PageRank passed. However, the PageRank is now divided equally among the links regardless of whether or not they have a nofollow attribute. In the example above, with this new change, each link would still receive 20%, but the contact us and about us page would receive nothing at all.

The change to the nofollow attribute will have major consequences for some websites. For example, a blog page may have 5 legitimate links and 45 “nofollow” comments. Now, instead of a 20% share, the legitimate links will receive a 2% share of the PageRank that is passed. This is a very simplified view of how link score is calculated, but the fact remains that this simple change to the nofollow tag could mean big changes for many websites.