8.3. The Mysterious PageRank

You might hear a lot of people talk about Google's PageRank, bragging about attaining the misty heights of rank 7 or 8 or speaking reverently of sites that have achieved 9 or 10. PageRanks range from (sites that have been penalized or not ranked) to 10 (reserved for only the most popular sites, such as Yahoo! and Google itself). The only place where you can actually see the PageRank of a given URL is the Google Toolbar [Hack #60], though you can get some idea of popularity from the Google Directory. Listings in the Google Directory contain a green bar next to them, providing a good idea of a listing's popularity without giving an exact number.

Google has never provided the entire formula for their PageRank, so all you will find in this book is conjecture. It wouldn't surprise me to learn that the formula is changing all the time; as millions of people try myriad methods to increase their page ranking, Google has to take these efforts into account and (sometimes) react against them.

Why is PageRank so important? Because Google uses that as one aspect of determining how a given URL will rank among millions of possible search results. But that's only one aspect. The other aspects are determined via Google's ranking algorithm.