The ‘face’ of Google’s search engine business, Matt Cutts, has written a helpful and revealing blog post explaining how Google PageRank works… what the ‘nofollow’ attribute does (and no longer does)… and why we should all forget about ‘PageRank sculpting’…

Matt Cutts’ post is a must-read for webmasters, Internet marketers and anyone remotely interested in search engine optimization (SEO). (Not that anyone would want to optimize their sites for the search engines… no, Matt, not at all…).

Here’s my take on Matt’s article (in English… minus the technical-bordering-on-math talk)…

Firstly, by way of background, PageRank indicates, on a scale of 0 to 10 (10 being the highest), the authority of a website in Google’s eyes.

PageRank is just one – but probably an important – element of how Google ranks a website in the search engines.

It’s certainly no guarantee of a high search engine ranking. After all, a lot depends on the given keywords. Also, PageRank can go up and down as a website’s link profile changes, and as Google revises its search engine algorithm.

The most popular websites, nevertheless, tend to have very high and stable PageRanks. This is probably because the links to such websites are also more legitimate and stable. Which means they probably come from websites with relatively high PageRank!

Therefore, there’s probably truth in the idea that the higher the PageRank of a given website, the more telling is PageRank as an indicator of both authority and search engine rankings.

So that’s the general idea of PageRank… now, how does it work? In other words, how does Google attribute authority to links on a given webpage, and therefore to a webpage?

Without explaining all the nuances of how Google calculates PageRank and PageRank flow, Matt indicates that these are based on the links Google counts as going to and from a given webpage.

In simple terms, a webpage with 9 incoming links and three outgoing links would mean the PageRank flow along each outgoing link would be 9
divided by 3, equating to 3 points of PageRank.

To prevent the possibility of PageRank flow reaching infinity, there’s also a decay factor of about 10-15 percent. In other words, about 10-15 percent of the PageRank on any given page disappears before the PageRank flows along the outlinks.

All well and good, but how does Google calculate PageRank flow for links on a webpage with ‘nofollow’ links coming into and/or out of the page?

Matt Cutts has provided guidance on this too, which we’ll address in Part 2 of this two-part series.

Source: Matt Cutts, “PageRank sculpting,” Matt Cutts Blog, June 15, 2009

This entry was posted on Monday, June 22nd, 2009 at 7:30 am and is filed under Kikabink Lab, Search Marketing. 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.