What is Google Pagerank exactly?

I get asked this question alot of times by my clients. I am still amazed sometimes at the ignorance of website owners. And, since I own a hosting company, I deal with website owners on a daily basis. I think it’s time to set the record straight on the whole PageRank topic.

Why Google?
If you own a website, and make your living off it, then the Search Engines are the all seeing, all knowing gods of your universe. And Google will be the chief cook and bottle washer in this equation. Some useless, but interesting facts about Google:
Google processes about 20 Petabytes of data per day. (A petabyte (derived from the SI prefix peta- ) is a unit of information or computer storage equal to one quadrillion bytes, or 1000 terabytes. IE - 20 Billion Gigabytes of data per DAY…)
At last count (March 2006) they handled about 91 Million searches/day

If you do a little research into PageRank, you’ll be amazed at how obsessed everybody is with it. And for good reason as well. Everybody wants a larger one. Everyone has ideas about how to increase it. (Some of them good. Some of them not so good. Others are just plain reckless and stupid.) Let me explain what it is, and how it works.

It’s no surprise then that Google is the leader in the search engine world at the moment. So where does pagerank come into play?

What it is

Firstly, when it comes to PageRank, there are three things you need to understand right from the start:
Everyone thinks that PageRank is important.
Nobody admits that PageRank is important. (Unless they have a high one)
Everyone is always interested in the size of everyone else’s

Pagerank is one of the many factors Google takes into account when it returns the results for a search term. It’s Google’s way of indicating how important a website is. It matters because it is one of the factors that determines a page’s ranking in the search results. It isn’t the only factor that Google uses to rank pages, but it is an important one.
PageRank is determined by an algorithm, and the main factor of this is algorithm is the amount of websites linking to a specific site, and what THEIR PageRank is.
You can basicly look at a link from site A to site B, as a vote from site A for site B. The higher site A’s PageRank, the more this vote will count.

PageRank is measured from 0-10. On face value, sites can be sorted out into three categories:

PageRank 0-2
- New websites that are just starting out. Websites that have come to terms with the size of their PageRank and have given up trying to increase it (but secretly hope it’ll still grow over time). Bad boys who have broken the SEO rules (and there are a lot of them).

PageRank 3-6
- Established websites that have proven they can perform. Niche websites that have a big enough PageRank to do what they need it to do.

PageRank 7-10
- In order to compete with this PageRank, one needs to develop other techniques to establish your own area of specialist expertise.

How is it calculated?

This is the Algorithm: PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn))

The way Google determines a page’s PageRank with this algorithm, is however a topic for a entire post, which I will do indepth at a later stage. I will give you the shorthand version though:

a page’s PageRank = 0.15 + 0.85 * (a “share” of the PageRank of every page that links to it)
where
“share” = the linking page’s PageRank divided by the number of outbound links on the page. This unfortunately also means that the more outbound links there are on a page linking to your site, the less PageRank value your page will receive from it.

As you can see this is quite a complex calculation. The PageRank of the individual pages in a site also plays a part in the final PageRank for a site. Also keep in mind that, while calculating site A’s pagerank, if site B is linking to site A, site B’s PageRank will be taken into the calculation. If site A’s PageRank increases due to this, and site A links to site B, so will site B’s. This in turn means that the vote for site A from site B will be worth more, and the whole process starts from the beginning again.
(How’s that for numbers crunching?) The equation shows clearly how a page’s PageRank is arrived at. But what isn’t immediately obvious is that it can’t work if the calculation is done just once. 40 to 50 calculations are needed, and this is precisiely what Google does at each update, and it’s the reason why the updates take so long.

Note that when a page votes its PageRank value to other pages, its own PageRank is not reduced by the value that it is voting. The page doing the voting doesn’t give away its PageRank and end up with nothing. It isn’t a transfer of PageRank. It is simply a vote according to the page’s PageRank value. It’s like a shareholders meeting where each shareholder votes according to the number of shares held, but the shares themselves aren’t given away.

How can I increase my PageRank?

SEO
Make sure your site is Search Engine Friendly. Make sure your META TAGS are in the correct format, so that you don’t get penalised on account of it. (This will also be the subject of a future post.)

CONTENT
By increasing the number of pages on the site, it increases the amount of PageRank the webmaster can play with. If those pages point (or link) internally then it can increase the PageRank of those pages for instance. Just be carefull not to create useless pages with no PageRank value, as it will affect your PageRank negatively, for obvious reasons.

ADVERTISE
Advertising your website is a core piece of your strategy. However, to really increase that PageRank, you need incoming, permanent, links not occasional pay-per-click ads or banners that can change day-to-day or week-to-week. Ways to do this include, writing high quality articles that get published on a number of sites (the author is still working on getting that one right), being active in fora associated with the subject of your website, and forming a group in one or more of the social websites.

LINK
I cannot stress the importance of this enough. Build links to other websites, and have them link back to you. (Called reciprocal linking). The more links pointing to your site, the better for you pagerank. Build links from sites with a higher PageRank than yours, if you can. Actually, this SHOULD BE YOUR GOAL.