In 2005, Google introduced the rel=nofollow attribute to help webmasters tell search engines which links they want to flow page rank to. It has been widely debated, criticized and still followed by a lot of webmasters. The reason, until last year, nofollow could be used to hoard pagerank on a certain website. To understand this, we need to understand pagerank and how it flows :
How does page rank flow?
This is better explained with simple examples, so we’ll consider 3 pages here :
- Page A, has a pagerank of 8 and has 4 links to other pages
- Page B, is one of the pages linked from page A with no pagerank of it’s own
- Page C, is also one of the pages linked from page A with no pagerank of it’s own
Traditionally, before the introduction of nofollow, the link juice from Page A would be divided by the number of outgoing links and equal pagerank would flow to all pages. So pages B and C got a pagerank of 2 each.
Let’s add rel=nofollow attribute to page C’s link on page A :
- Page A’s pagerank would be divided by 3 instead of 4 to benefit links without the nofollow attribute
- Page B would get 8/3 pagerank
- Page C would not receive any pagerank
The current situation
About a year ago, Google started adding all outgoing links on a page to the denominator even if they were nofollowed, making the nofollow attribute useless for sculpting pagerank. Here’s an example when Page C is still nofollowed:
- Page A’s pagerank would now get divided by 4 (number of outgoing links)
- Page B would receive 8/4 link juice
- Page C receives no pagerank
- Link juice worth 8/4 has evaporated and not benefited any page
In this oversimplified version, an important factor of pagerank distribution has been ignored. Google never allows pagerank to flow completely from one page to another. There is a loss of approx. 10% to 15% while calculating the pagerank flow to the next page. This is to prevent Pages A and B linking to each other in a closed loop (assuming page A removes all other outgoing links) and achieving a pagerank of infinity.
Let’s complicate things :
Imagine an actual website, for example, let’s consider this blog. Each page on this blog links to several categories, tags, other pages, and the homepage. This page can be found through multiple categories and tags and will also remain directly linked from the homepage for sometime. Some people will link directly to this page from their websites, some will link to articles from which this page is linked and some will link to articles from which this page is 3 clicks away. Each article has a different pagerank and different number of links on it. Each page on this site, has no fewer than 30 links pointing to internal and external links, some which are followed and some are nofollowed.
In such a scenario, to effectively sculpt pagerank, a huge amount of calculation is required to judge the value of each outgoing link. Considering websites such as this are quite dynamic in nature, fresh calculations need to be done every time a new article is posted or someone links to a page on the site.
Let’s make things simple :
Pagerank sculpting, is probably one of the most useful or useless things a webmaster can invest his time in. While it is important to observe how pagerank flows in and out of your site, it’s not the best use of your time. A simple checklist will help you manage links on your site better :
- Since almost every page on a website links to the homepage, link your best articles, highest conversion pages etc. from the homepage. If possible, use bigger fonts or images to link to these pages. This will ensure that these links receive more weight-age than other outgoing links from the frontpage.
- Make sure you nofollow all links you don’t vouch for or want pagerank to pass to. This is very easy to go overboard with, so stick to nofollowing all links which you haven’t personally authorized. Such links usually are links found in member signatures in forum posts and links in user comments on blogs.
- Hide or move : Continuing from the last point, it’s more useful if you can hide such links from search engines altogether, so that your page retains it’s maximum ability to distribute link juice internally(*). For vBulletin forums, vbSEO does this extremely well by hiding signature links from search engines, but still making them visible to logged in members. For Wordpress, a delink comments plugin can be used to selectively delink any comments. Wordpress also allows you to move comments to a separate page after a certain number of comments have been received. While this kind of pagerank hoarding can prove very helpful, it should be used with caution. If user participation is important to your website, such a move might severely impact contributions from members. Webmaster Blog rewards regular comment contributors with followed links.
In conclusion :
Hoarding pagerank is too complicated to be done for each link, but simple rules can help ensure that your pagerank flow is optimized. Trying to over optimize the flow can create problems for user experience and hurt search engine rankings. Nofollowed links are also a big problem for link building strategies.
As a webmaster, instead of putting too much emphasis on sculpting page rank, more benefit can be gained from creating and publicizing useful content that people want to link to. An outgoing followed link to another website, usually does more good than harm. Make sure you are not linking to any spam or blackhat SEO site, and you’ll be fine.
(*) If a page has 100 outgoing links and 98 are comment links, then the pages that the article author linked to will receive 1/100 link juice instead of 1/2 link juice without the comments on the page.
(**) Outgoing links refer to links leading out of the page. The link might lead to another page on the same website and will still be referred to as an outgoing link for the purpose of this article. This is because, Google distributes the same pagerank to links going to another page within the same site, or link leading to another website.
You have been reading part 2 of our Complete guide to pagerank. Please subscribe to our feed for future articles.
Part 1 : All about pagerank
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