Google page rank

Why Googles page rank changes

[Carl_R]

Does anyone know why Googles page rank changes by the hour (at least on my site). I can check my site and find no page rank on my sub pages then it will be back the next day (PR 3). I have good links, some recipricle, some not. One has a Google rank of 7 and is one way to me, but Google does not care, But Yahoo and MSN do. Also 90% of our links are related to the pages they are linked to (we have many links to sub pages). I realize Google is basically just I giant "yellow page directory" as some else here on this forum stated, but as someone who has been in retailing 27 years and used yellow pages to get new customers, I find Googles constant rule changing very unprofessional and worse.

[jdMorgan]

Google is not "one giant yellow pages book," it is thousands of books, each published at a different time, and each being constantly revised. Thus, the individual copies differ.

This is because Google is not one computer but thousands, distributed across the globe in many data centers. These machines are updated in small groups or individually according to load, so at times, there may be no two alike.

Due to load-sharing, each time you connect to google.com, you may (and most probably do) get a different server at a different IP address. This accounts for many of the phenomena observed here; bouncing PageRank, shifting rank on the search results pages, recently-updated pages listed one minute, old pages the next, etc. Google is a huge network of inexpensive PCs, not a single, centralized supercomputer.

You can 'nail down' google.com to a particular IP address if you so choose, by modifying your computer's 'hosts' file and entering the IP address of the Google server you always want to use. This by-passes the normal DNS lookup that your browser performs to translate the google.com domain name to an IP address, and instead uses the fixed entry you created in the hosts file. It works as long as they don't de-provision the IP address that you chose. However, this is similar to going to sea with two clocks: If they disagree, which do you trust for navigation purposes? In this case, you have a thousand clocks, and they all disagree - at times. :)

Jim