Backlinks in Search Engine Optimisation – Value and Limitations: The Nofollow Attribute
Search engine optimisation (SEO) is the application of verifiable techniques that improve positioning of web pages for targeted keywords on search engine results pages to drive more visitors to a website. A backlink is a link placed on another website back to the writer’s website.
The Google co-founders, Larry Page and Sergei Brin, observed that the best websites attract links from other websites and they set about incorporating link related data into their search results positioning algorithm. Google has become the most popular search engine accounting for 90% of searches in the UK for example.
A study of the opinions of 72 leading SEO experts commissioned by SEOMoz. and presented on their website from August 2009, found that four of the top five factors in the Google algorithm relate to links.
A link from one website to another is a vote or commendation conferring authority. The total authority value of the incoming links to a web page is indicated by its PageRank. A new web page has a PageRank of 0 whereas the web pages with the most incoming link value, such as Google.com, have the maximum PageRank of 10. The PageRank scale is logarithmic. For every web page with PageRank 10 there are 10,000,000,000 web pages with PageRank 0. The value of each link is calculated as the PageRank of the linking page divided by the number of outgoing links on that page and it can be measured in Link Authority Units.
The top factor in the Google Algorithm that determines positioning on their results pages is the PageRank of the home page of the website. Home pages that are themselves competing for a keyword receive a boost in their effective PageRank – the second factor in the Google algorithm.
There have been numerous articles promoting the concept that backlinks provide enormous benefit in terms of enhancing authority by increasing PageRank. We must, however, look at the evidence to see whether such backlinks are truly effective from an SEO point of view.
There is clearly a world of difference between the significance of a link placed spontaneously by a webmaster to another website and a backlink placed by a webmaster on another website back to his own.
Every search engines has a commercial interest to provide the best possible results for a search. Google has an income of billions of dollars from the advertising option it provides – Google Adwords. It would seem unlikely, that the facility to place limitless backlinks all over the internet would be considered by search engines as fair and acceptable means to overcome their quest to provide ordered natural search results based on merit alone.
In 2005, Matt Cutts, Google’s lead for spam detection, and Blogger’s Jason Shellen designed the “nofollow” HTML attribute. This addressed the problem presented to them by growing scam backlink activity. Google announced that hyperlinks with rel=”nofollow” would not influence the link target’s PageRank. A link with a nofollow attribute can be easily identified by looking at ‘View’ and then ‘Source’ on your web browser. The “nofollow” attribute has no effect on the traffic that follows the link.
Backlinks and off-page optimisation:
For webmasters, a backlink presents two potential opportunities; it brings visitors and it has the theoretical advantage to enhance authority and thereby increase PageRank. Attracting links is crucial in search engine optimisation and it can be no surprise that an industry has developed focusing on backlink placement for off-page search engine optimisation. Backlinks can be placed on website directories, article directories, social network and social media websites.
There are boundless, unscrupulous offers on the internet to purchase vast numbers of backlinks. The search engines, however, are fully aware of them and have counter-measures in place to prevent gross abuse of the system. Otherwise, the benefit to the search engines of using appropriate links in their algorithms, that are specifically designed to give the best web pages top positioning, would be destroyed. It is all too simple for the search engines to recognise irregular backlinking activity as surges that are blatantly unnatural. These links will be automatically excluded from contributing to authority and PageRank.
Blogs, Social Networks Including Facebook and YouTube:
The most popular place to put backlinks are social network and social media websites and blogs. The most popular social network website currently is Facebook with 24 billion visits each year. YouTube, with 9 billion visitors annually, focuses on uploads of videos from the public and allows comments to be made.
The “nofollow” attribute was originally designed to reduce spam on blogs. Spam affects the blog community and spam on blogs could potentially weaken or destroy the benefits of blogging.
YouTube was bought by Google In November 2006, for $ 1.65 billion, and it now operates as a subsidiary of Google. The author regularly uploads videos to YouTube and is permitted to include a backlink. The backlink may attract viewers to his websites but the links have the nofollow attribute and therefore do not add authority or increase PageRank.
Backlinks on Facebook and many other social network websites similarly have the nofollow attribute automatically applied.
The application of the nofollow attribute has moved beyond just blog comments. Directory listings that are either unpaid or are not reciprocally linked often use the nofollow attribute. The no follow attribute prevents outbound links leaking away precious ranking link juice that could otherwise be retained within the directory or allocated to preferred websites.
It is in the interests of article directories to provide incentive for authors to place articles of quality with them. The best article directories are peer reviewed before articles are accepted for publication. These websites offer authors a resource box which acts as a brief curriculum vitae and one or two links to the authors website(s).
In 2009, I submitted an article to EzineArticles. The web page featuring the article currently has acquired a PageRank of 2. The nofollow attribute has not been applied to my links. There are 60 links on the page and the value of the links to my two designated websites is 2/60 – 0.0333 l.a.u. I would emphasise that the PageRank of 2 for my article results from the spontaneous links generated to it. Only articles worthy of spontaneous links will develop PageRank.
Two types of programs are being promoted to increase the benefits of internet article submission – automatic article submitters and article spinners. The automatic article submitters can send an article to the hundreds of article directories. Article spinners permit the author to create hundreds of variations of an article with different synonyms so that the search engines will not spot the duplication and discount all but one of the submissions. However, even with spun articles, I have little doubt that the surge of articles on the same topic and with the same backlinks will be recognised by the search engines and discounted.
Implications of Backlinking:
What are the implications of the search engine counter-measures against backlinking for off-page search engine optimisation?
Backlinks remain a valid highway from another website to your own but their value in terms of acquiring link juice and thereby increasing PageRank is limited.
It only requires a few hundred links to achieve PageRank 3 status and a few thousand to acquire PageRank 4. Only backlinks on web pages with PageRank and without the nofollow attribute can contribute to a website’s authority and PageRank. Backlinking campaigns must be carefully orchestrated with slow, steady and stealthy acquisition of backlinks in order to stay under the Google radar and have a chance of being worthwhile.
Successful top positioning on search engine results pages for high difficulty keywords is the objective of search engine optimisers. Analyses have shown that only websites with home page PageRank of 5 or more have any realistic chance. PageRank 5 requires tens of thousands of backlinks and it is the author’s opinion that this can only be achieved by the quality of the content of the website encouraging natural links and not by intensive backlinking campaigns.
Recommendation for Website Owners:
Website owners considering investment in off-page optimisation through an SEO firm should seek evidence of effectiveness of their work before placing a contract.
David Viniker MD FRCOG is a doctor trained to practice evidence based medicine. He has applied the principles of evidence based practice to SEO. He has developed a new, essential keyword tool – Keyword SEO Pro http://www.KeywordSEOPro.com that determines keyword difficulty based on the top factor in the Google Algorithm – PageRank – of the top positioned web pages for a list of potential keywords. This allows search engine optimisers and website owners to focus their resources on keywords within their website’s range for top positioning on the search engines. His website http://www.firstwebsitedesign.com provides valuable information for beginners and intermediates in website design and search engine optimization.