Understanding Google PageRank

Understanding Google PageRank is not as mysterious as some would have you believe.

So what exactly is PageRank and how does it affect your rankings in the search engines? This article will set you straight on this often misunderstood topic.

PageRank is essentially the measure of a web page's importance relative to all other web pages. While no one knows the exact algorithm Google uses to calculate PageRank, one of the major factors is the number and quality of inbound links pointing to the page in question.

The key to understanding Google PageRank is to realize the democratic nature of inbound links. A link to your page from some external site is really a vote or "thumbs up" for that page. The more votes (i.e., inbound links) a page gets, the more important the page must be.

While your Meta tags and main page keyword help determine the relevance of your page, PageRank determines the importance of that page. When Google returns search results, it wants to return a page with the highest relevance AND the highest importance.

Understanding Google PageRank - Toolbar vs Actual

There are actually two different measurements for PageRank; Toolbar PageRank and Actual PageRank. We won't be making a distinction between the two in this article, but the difference will help in better understanding Google PageRank.

Toolbar PageRank is a numerical value between zero and ten. A value of zero means the page is not ranked yet while a value of ten conveys the ultimate importance.

Toolbar PageRank gets its name from the fact that the Google Toolbar available for your web browser can display PageRank values for whatever page you happen to be viewing. For example, while I may personally feel that the homepage of Britney Spears is of little importance, Google disagrees with me and has assigned it PageRank of 7 (which is a very good score.)

An important thing to keep in mind is that the PageRank values are logarithmic. That is, a PageRank value of six is not twice as good as three, but perhaps thousands of times better. Therefore, it is more difficult to move up a notch the higher you get. It's relatively easy to move from a PageRank of one to a PageRank of two, but much more difficult to move from a five to a six.

Actual PageRank is a numerical value that Google assigns each and every web page. The lowest value for Actual PageRank is 0.15 and no one really knows what the highest value is (but it's most likely in the millions.)

Toolbar PageRank allows us website owners to get a quick numerical PageRank check. It's only updated every 3-4 months so it is pointless to look up your values on a weekly or even a monthly basis.

Actual PageRank seems to be a dynamic system that is updated and changing all the time. Google uses the Actual PageRank, as opposed to Toolbar PageRank, to determine how to rank pages by importance.

We can summarize our discussion so far as follows:

PageRank measures the importance of a web page.
PageRank does NOT measure the relevance of a page.
PageRank is a relative and not an absolute measurement.
Toolbar PageRank is a numerical ranking system between zero and ten.
Actual PageRank is a dynamic value between 0.15 and some high value in the millions.
PageRank is logarithmic, not linear - the higher you go, the harder it is to move.

The rest of the article will not make a distinction between Toolbar and Actual PageRank.

Understanding Google PageRank - PageRank Flow

The key to understanding Google PageRank is to realize how it flows into and out of web pages. In actuality, PageRank flow is quite complicated. However, you can get a good basic grasp of how it works with the simplified description below.

PageRank flows to your page (as long as someone is linking to it) as well as out of your page (as long as you link to some other external page.) If you have 25 outbound links on a particular page, each link would receive 1/25th of the total PageRank of your page. If your page has a low PageRank value, these 25 links won't be passing much "link juice." However, if your page has a high PageRank, your outbound links will be more powerful.

Similarly, your web pages will accrue PageRank from every link that points to them. Links from pages with high PageRank will help increase your own PageRank faster than links from pages with low PageRank. This is why the quality of inbound links is more important than the quantity. It's much better to have ten PageRank "7" links flowing to one of your pages than 100 PageRank "1" links pointing in. This is a critical point in understanding Google PageRank.

Keep in mind that you link out to a page from one of your own pages, you are not "giving up" any PageRank. You're simply passing it on. There is no reason to fear linking out to valuable material if it benefits your web visitors.

If, however, you wish to link out to page but don't wish to pass on your PageRank, you simply use the "nofollow" attribute within the HTML link code. Google will still be able to see the link but will not allow your PageRank to pass through. Below is an example of a link using this "nofollow" attribute.

<a href="free-software.html" rel="nofollow">Free Software</a>

Why would you want to do this? In order to "sculpt" your PageRank and redistribute it to more important pages. By using the "nofollow" attribute in links that point to low content pages within your site (contact forms, legal notices, privacy policy, etc.,) you allow the other links that point to more important pages to carry slightly more power.

Similarly, if you have any outbound links that are not really providing your visitors useful content (e.g., Verisign and Hacker seals,) tag them as "nofollow" and you'll save some extra PageRank for the other links on the page. Remember, links with the "nofollow" attribute will still work just fine for your visitors, they simply won't pass PageRank.

Don't go crazy with this technique as it is simply for fine-tuning on the granular level. Building quality inbound links and adding keyword-rich content that your visitors will want to read is 95% of the game. Spending large amounts of time trying to fine-tune your flow of PageRank is not time well spent.

Understanding Google PageRank - Conclusions

As you can see, understanding Google PageRank is not all that difficult, but there is a lot of confusion on how a page accumulates PageRank, how it flows from page to page, and how it affects your rankings in the search engines.

While PageRank is not the magic pill, it does make sense to monitor it on a quarterly basis. However, don't make it your only website optimization goal. I've seen sites with low PageRank outperform sites with significantly higher PageRank. Remember, it's not just the importance of your page, but also the relevance..

If you spend time building your Link Popularity and work to maximize your On-Page Criteria, you'll be well on your way to increasing both the overall importance and relevance of your site. Higher PageRank will naturally follow.