I don’t even know where to start with this one, Google is an absolute beast, and certainly not something that I take lightly when writing about ‘how it works’. Google Page Rank is relatively new in the world of search engines and is a very interesting addition the wealth of factors that decide where a site gets ranked.

Page Rank operates on a scale of 0 – 10 and is basically an indicator of the ‘importance’ of your site in Google’s eyes. The next immediate questions, obviously, are how do you know what your page rank is, and how does Google determine whether or not your site is important?

Read on.

To find out what your page rank is (and everyone else’s) simply download the Google Toolbar for FireFox, or explore any other of the FireFox plugins that will do the same thing.

Your Page Rank is determined by a number of factors, the first and (to an extent) the most important of which, how many sites link to you. So, ebay, facebook, and myspace all have a pagerank of 7-9 because literally hundreds of thousands of sites link to them. A small (or new) site will likely only have a PR1 or 2, because it has not yet established many inbound links. Your ‘link popularity’ as discussed in my previous post about SEO Stat Packages, will give you a number, for how many sites are linking to you, and give you a comparison of other sites similar to yours and how you rank amongst them in terms of inbound links.

Now so far this sounds pretty basic, more links = more page rank, but it goes much deaper than just that little equation.

Page rank is passed on from site to site, so for example site1.com links to site2.com which links to site3.com

Site1.com has a PR7, so Google knows that this is an important site, because site1.com links to site2.com Google thinks site2.com is important too (ebay wouldn’t just link to any old little website, it links to other important sites like bbc and .gov websites). So if a PR7 site links to anther site, it passes on some of its PR. So site2.com which would ordinarily be a PR3 is boosted up to a PR5. Site2.com links to site3.com and puts it at a PR3.

But, if site2.com turns out to be a hacker/spammer website, using poor SEO techniques and Google finds out then it implements a penalty. Site2.com is marked as a dodgy site, and its PR is pretty much shot, but the buck doesn’t stop here, it affects the whole network. Site1.com is a big important site, and its linking to a bad site, this looks very bad, so it’s PR is also penalised and it drops to PR6. Similarly site3.com is no longer getting an inbound link from an important site, because as it turn out, site2.com is not an important site at all, so it no longer receives any PR benefit from site2.com and drops back down to a PR2 – but it is not penalised any further because it has not done anything wrong.

Obviously people have tried to cheat this system, building up high PR sites and then selling links to benefit other people’s PR, but as of December 2007 Google have penalised pretty much every paid directory out there.

It used to be the case that your home page was considered your primary source of PR, and generally PR would drop by one for each subdirectory/subcategory of the site, nowadays however, page rank is assigned very much on a page by page basis, and its not uncommon for a single page of a site to have higher PR than the root index.

Page Rank is updated sporadically, so don’t expect to see it change on a daily or even weekly basis – generally there are PR updates that happen every few months, but even then it can be questionable as to how many sites actually get an update.

Page Rank is a tricky beaver, but you definitely should not focus too much on it, many people try too hard to get a higher Page Rank, when in reality it isn’t affecting their rankings that much. PR is supposed to be a natural thing, thats how it was designed, so if you focus making the site as good as it can be, then people will naturally link to it, and you will see the benefits in your own PR.

What experience have you had with PR? Have I missed something major? Drop me a line in the comments!

This entry was posted on Wednesday, February 20th, 2008 at 12:39am and is filed under Google. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.