There is a great deal of confusion about Google PageRank, one of the key – but optional – components of the Google Toolbar that you should have installed on each of your Web browsers. Pared down to the basics, PageRank is a numerical value, on a scale from 0 to 10, that indicates the importance of any page of content on the Web, based upon the concept that one page linking to another is essentially casting a “vote” for the importance of the second page. Not a truly democratic process, more “important” pages, based upon their own PageRank, carry more weight than pages that have been deemed to be less important, but the bottom line is that Google calculates each page’s relative importance from the “votes” that it has received. Certainly, anybody with even a rudimentary understanding of SEO (search engine optimization) can understand the importance of inbound links to a site.

You might ask, “Who cares?” You should! Those websites that you need to provide links to yours will often make their decisions based upon your the PageRank of your site’s Home page (or other linking page). Every webmaster would like to exchange links with a site with a PageRank of 7 or 8, but nobody wants to waste their time linking to a site with a PageRank of 1 or 2 (or even zero). More importantly, PageRank is an important factor in helping to determine a site’s ranking in the overall organic search results.

On the same token, you (or your webmaster) will want to take PageRank into consideration when you consider linking to other sites. Again, this is not a truly democratic process, and not all links are treated equally. For example, Google will filter out links from known link farms. Because incoming links from link farms are beyond any webmaster’s control (and link farms are more likely to try to capitalize upon a link to you if your site has a higher PageRank), Google will not penalize you for inbound links; however, you will be penalized for any outbound links to link farms or other penalized sites (often represented by a PageRank of zero).

What other factors come into play in determining the relative importance of one link versus another? For one, the number of links on a page. All else being equal, a link to your site from a page with only that one link is far more valuable than a link to your site from a page with 50 links. Basically, the more links on a page, the less PageRank value your page will receive from a link.

A few other points:

• PageRank values are not arithmetic. Nobody outside of Google’s upper echelons knows the formulae, but it is generally agreed that the scale is logarithmic. In other words, it takes a lot more to advance from PR4 to PR5 than it takes to advance from PR1 to PR2.
• A site’s total PageRank (the combined PageRanks of each of its component pages) is also an important measurement. More than anything else, this is determined by the number of unique pages within a site, clearly benefiting larger sites. New pages (“orphans”) should be directly linked to existing pages in order to yield any benefit for the PageRank of the overall site.
• Links to pages with no outbound links of their own (or pages that Google has not indexed) are known as “dangling” links and have little or no value.
• There are many experts who agree that outbound links that are not reciprocated can be a drain on a site’s total PageRank.

Because the Internet is constantly growing, the logarithmic scales that determine PageRank, by definition, must be continually evolving. This results in frequent changes in a page’s PageRank, where the measure will either increase or (more likely) decrease by a numerical value of 1 for no apparent reason, typically on a three-month basis. This phenomenon is referred to as the “Google dance” and is one more reason why it is important to continually build a site (by adding to its content) and to continually work on building the site’s number of inbound links from other highly-ranked sites.

Interesting tidbits:

• According to Wikipedia, the name “PageRank” is a trademark of Google, and the PageRank process has been patented; however, the patent is assigned to Stanford University and not to Google. Google has exclusive license rights on the patent from Stanford University. The university received 1.8 million shares in Google in exchange for use of the patent – shares that were sold in 2005 for $336 million.
• The name “PageRank” is derived from the name of its developer, Larry Page, one of the two founders, along with Sergey Brin, of what would become Google in 1998. The original search engine that Page and Brin developed as part of their research project at Stanford University in 1995 was called “Backrub”.

Learn more. The following references are listed in order of increasing complexity, ending with Page and Brin’s original research paper:
http://en.wikipedia.org/wiki/PageRank
http://www.webworkshop.net/pagerank.html
http://www.ianrogers.net/google-page-rank/
http://infolab.stanford.edu/~backrub/google.html

One of the most effective ways to improve your website’s organic search engine position is to increase the quantity and quality of both inbound and outbound links to established, highly rated sites. As an added benefit, any inbound links are going to directly increase the amount of traffic from the referring sites which provide the links. Too many people obsess over the concept of “reciprocal links”, and this is unfortunate. Whether or not another site provides a reciprocal link is not nearly as important as the links themselves, even if they are one-way links. Let us take a separate look at inbound and outbound links.

Outbound links from your site to another site should provide your visitors with sources of additional information that relates to your business or your site’s content. Let’s say that you own a business that sells small kitchen appliances, it would be a good idea to provide links to the manufacturers that you represent, independent product reviews, and general consumer information on the various appliances. By doing so, you are enhancing the usefulness of your site to its visitors (and lessening the likelihood that they might choose to turn elsewhere … perhaps a competitor … for that same information). Simply by association with these sites, your site’s own search engine ranking will improve.

There are a few guidelines when setting up outbound links:
1) Setup the links to open in new tabs or browser windows so that your visitors do not lose track of their point of origin.
2) When choosing outbound links, try to find sites that are, in themselves, highly search rated. A good reference is a site’s “PageRank”, as indicated by the Google Toolbar that you should have installed on your browser. (It’s free!) Try to choose businesses that have a PageRank that is as high or higher than your own.
3) Links that are anchored to text (such as my Google Toolbar link, above) are more valuable than links that are anchored to graphics. If possible, use the two in conjunction.
4) Links that relate to the content that appears on the linking page is more valuable than more general links.
5) Do not include more than a maximum of 50 outbound links on a page.

Inbound links from other sites to yours are even more important. Most of the same guidelines still apply. Every link counts when determining your search engine ranking, as long as it appears on a recognized page of a highly rated site. What you don’t want (but probably cannot prevent) are incoming links from so-called “link farms” which are trying to build their own search engine ranking by capitalizing upon their outbound links to your sites and hundreds of others, typically with totally unrelated content. Obtaining inbound links from the same websites to which you are supplying outbound links should be one of your top priorities, particularly if their websites are more highly rated than your own. The appliance manufacturers, for example, may have links to “where to buy our products”. Try to insure that your business is not only listed but that there is a link to your website. Inbound links from any directories that relate to your business should be your next priority. Don’t forget to include blogs, and even appropriate MySpace and Facebook pages. Whatever effort you put into link creation today will pay dividends tomorrow. In difficult economic times, I can’t think of a better way of helping to insure your continuing success.