SEO Explained - Page 13
Building Links to your website

So far, we've covered changes to your website’s backend structure.   This type of SEO is referred to as “On Site Optimisation”.    The other important aspect of ensuring that your website ranks well is ensuring that other websites link to your site.   This practice is referred to as “Off Site Optimisation”.

The background behind Link Building

The fundamental insight that made Google the massive juggernaut that it is today, was the development of the Google PageRank™ algorithm.   Stripping away a whole pile of PhD mathematics behind PageRank™, leaves the fundamental insight that Larry Page and Sergey Brin realised.   The more people who link to your website from theirs, the greater the chance that your website will be of interest to people when they search.

If you have an appetite for the detail behind this, a great site with and in-depth explanation can be found at http://www.webworkshop.net/pagerank.html.

Essentially a link to your site from a 3rd party site is a vote of its popularity on the search engines.   For a while Google was the only search engine employing this approach, but over time as Google was shown to have better and more relevant results than other search engines – the other search engines copied this approach, and these days building links to your site from other sites helps your ranking on almost all the search engines.

What’s an inbound link?

say your website is www.nikesneakers.com  …..then if I own www.usafootwear.com, and I link to your website from mine – then this is called an “inbound link” or sometimes referred to as a “backlink”.   Building as many backlinks as you can to your website will help your ranking.  

PageRank™ explained

When building links to your site, a key question comes up which is “what’s the PageRank of the website who I’m requesting a link from”.  This is relevant, as a link to your site from another site is more valuable, if the other site in question is itself a popular site.   As mentioned above – PageRank™ is a method than Google use for assessing a website’s popularity based on links pointing to it.   There’s an easy way to identify the PageRank™ of a website, and that’s to install the Google Toolbar.

The Google Toolbar has a PageRank™ indicator on it which shows you the PageRank™  of any website which you visiting.

PageRank™ is on a scale of 1 through 10.  It’s a bit like the Richter scale, in that a 2 is far bigger than a 1, and 3 is far bigger than a 2 etc.  Mathematicians refer to this as a "logarithmic" scale.   So while it’s relatively easy to achieve a 3 or 4 PageRank, achieving a 5 is much harder, and a 6 is very hard to achieve.   A  PageRank™ of 7 is usually only found on very large popular sites, and 8’s and above only on the largest sites on the internet.   

When looking at websites, ideally achieving links from websites with a reasonable PageRank (>=4) is what you’d want to aim for.   This is a bit of an over simplified analysis (there are other factors in determining value of links from other sites – such as how many outbound links exist on the page which is linking to you), but this basic principle should stand you in good stead.

Page 14 - Techniques for Link Building