Many people sees google pagerank as a measurement tool for viewing the importance of a , even other big webmasters trust pagerank to be correct, but it cant be further from the truth.
For those how want an introduction to what Pagerank is.PageRank is a numeric value that represents how important a page is on the web. Many are many aspects to consider when trying to get a higher pagerank, just to mention some of them, links to your website from others, onpage optimization, for how long your website has been online etc. its a fulltime job just trying to keep up with the adjustments made by google.
Many people sees google pagerank as a measurement tool for viewing the importance of a specific website, even other webmasters trust pagerank to be correct, but it can't be further from the truth. Google page rank has in the last year + more been very unstable, I have seen website going from a pagerank of 1 to 5 within a month, and some sites going from 8 to 2, even newly added website having quite high pageranks, without even having any traffic to their sites.
So why are people still using this as a trusted tool. well its quite simple, people still reads all the old articles on the internet saying, what a wonderfull tool it is, and people just got stuck in the old rutine, well get out of it and try to do some reasonable analysis on webpages.
Note:Other people tend to use a website called alexa to see the importance of a website, this website is actually quite effectiv, or it was, now I see alot of website get highly ranked there to, because they once or twice have bought some cheap traffic and then alexa has rated them based on their visiors amount.
Conclusion.So if your using eighter google pagerank or alexa to analyze websites, do it with caution, be carefull not to only use these tools, be creative instead try other ways, you may even discover new alternatives others have never thought of. For example try to see what are the most used keywords for a speciffic subject, then see what website is shown first in both google, yahoo, msn and more.