The Quest For PageRank - How PR Works

Google PageRank - it’s what all web designers, web masters, and bloggers covet. Despite this desire for a higher number, an aura of mystery surrounds both Google and it’s PageRank - and for good reason. Google’s inner-workings is a closely guarded secret. However, back when Google first started they published the equation that calculates PageRank. They most likely use a variation of that equation, but the original will be good enough for our exploration purposes.

The Formula:
PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn))*
where t1 and tn is the pages linking to Page A, C is the number of outbound links on Page A, and d is the ‘damping factor’ - which is normally 0.85.

If you’re mathematically challenged (like me) - here’s a simpler way of looking at it:
Page A’s PageRank = 0.15 + 0.85 x (a share of the PageRank of every page that links to it)

Basically, get links - get PageRank.

But there’s more to it than just links - so let’s dive into that.

When Page B links to Page A, Page B is ‘voting’ for Page A. Page A’s new PR is Page B’s PR x 0.85 + 0.15.
If Page B and Page C links to Page A, then Page A’s new PR is Page B’s x Page C’s x 0.85 + 0.15.

Simple, right?
Well, it seems so - but there is more to consider.
To keep this post manageable, I’ll speed through them.

If you look closely at the equation, you’ll notice that the worth of the link is divided by the quantity of links on that page. Thus, the more links on one page, the less they’re worth.

Google’s PR system isn’t the smartest. For example, http://plainbeta.com, http://www.plainbeta.com, and http://plainbeta.com/index.html are different pages to a crawler.
(So standardize your pages!)

The maximum PR increases as the number of pages on the site increases. So the more pages you have, the greater your PR can be. This is why you should submit your sitemap to Google through Google’s Webmaster Tools. If you’re a blogger using Wordpress, use the Google Sitemap Generator to index your site and submit it to the Google God.

Paid links are another thing to consider. In fact, there has been quite a hype in the past with bloggers losing their PR because of paid links and then getting it back by removing them.
So, don’t put paid links on your site if you’re concerned about PR - if you do, you’ll be penalized.
Update: However, if those links have “nofollow” (What’s NoFollow?) enabled, then it’s alright to have them. However, Google can be finiky, so things could get a little hairy - but you should be alright. (thanks to David Airey for the reminder)

And link farms… Some people believe they’re great - others don’t. If you get a link on a link-farm - it won’t be worth much. Remember what we learned earlier, the more links on a page - the less they’re worth. And often, Google will ignore link-farms in their calculations. Furthermore, if you link to a link-farm, you could be penalized.

And finally, Cookie-cutter pages (multiple pages that are exactly or nearly alike) can penalize your site. If you were to buy half a dozen domains, and put the exact same thing up with links to your web site(s), that would be a cookie-cutter site. That could spell trouble.

Want to get some tips on how to increase your page rank?
Check out the next post in The Quest for PageRank series: How to Increase PageRank.