Introducing PageRank

In a nutshell, PageRank (PR) measures the quantity of incoming links to a given web page and their relative strength. When one page links to another, it “casts a vote” for that page in the form of a PageRank value.

In general, the more links you have that point to your site the better, as this increases the PageRank of the page being linked to. The number of links that point to a site is also sometimes called link popularity.

However, the amount of PageRank value these links “forward” on to your site, and hence the amount that is used in the Google PageRank calculation, is diluted by the presence of other links on the same page. This is where link strength comes into play.

The greater the number of other links on a page, the weaker the strength of each individual link. Each link is essentially a “vote” for the page being linked to, and the strength of that “vote” is divided equally among all other links on the page. Which means, all other things being equal, if someone has a link to your site on their page with 100 other links, you won’t get any appreciable value from that link in the overall calculation, UNLESS the page has a very high PageRank score. Confused? All will be explained in the next chapter!

Tip: There is some confusion around whether you should spend more time getting a few links from pages with high PageRank or whether to get lots of links from pages with low PageRank. Rather than fret over this, my advice is simple - just acquire links! Today’s site with a low PageRank can be tomorrow’s site with a high PageRank, and even vice versa.

Note: In mid-November 2003, Google introduced a major algorithm change during the so-called “Florida Update” that changes the way Google ranks certain websites. It is believe these changes mainly involve how PageRank is computed – more accurately that PageRank is being phased out by a new “LocalRank” system of computing PageRank dynamically on the fly. At this writing, this new algorithm is still changing, with some of the effects not well understood. For more information, see the applicable section Appendix D – About the Florida Update”.