关于Google PR值的一些知识

1.什么是PR值？
What is Google PageRank?
Google PageRank (one word) is the measure of an Internet page based on the number and importance of a site’s incoming links. It is expressed as a numerical value, from PR0 to PR10, with PR10 being the highest possible PageRank (PR). Very few websites achieve that PR 10 level, of course.
Each level is more difficult to reach than one previous. The system is based on an exponential scale, similar to the earthquake Richter Scale. The only difficulty with the Google PageRank scale is no one is entirely certain how the numbers are calculated.
Incoming links for web pages are, in the opinion of Google, votes in favor of that page. On the other hand, Google considers some votes to be more important than others. The simple number of incoming links to a page is calculated by Google, but the relative importance of the “voting page” is given even more weight in the mathematical formula.
The pages that are considered to be more important votes, in turn increase the importance of the page they link. More important pages pass along more voting power. This is measured numerically as PageRank.
Note carefully, that PageRank is for each individual web page, not the entire web site as a whole. Every page in the Google data base has its own PageRank. Sites don’t have “rank”. Every separate page, however, on your website has its own PageRank.
Always keep in mind that PageRank is not the same thing as your site’s ranking on the search engine results pages (SERPs). They are entirely separate items. PR is the relative importance of a page on the web, expressed as a number. The SERPs are where your site appears on a search for your keywords.
以上英文文章是引用过来的，大致讲解的内容是PR值的定义和作用，总的来说PR值是谷歌计算网页的重要程度的一个算法。

2.PR值算法?
PR值算法网上有很多公式，但是多数是计算外部链接的，这个意义不是很大，以为对于我们中小企业外部链接的数量很有限，而且有时候也没有办法或者机会去选择更好的链接。
之前看过一篇文章是专门针对网站内部结构的计算的方法的，可以刚才没有找到，日后找到了再把相信内容介绍给大家。

3.谷歌的青睐？
中小站点确实是谷歌的青睐，但是我们不能否认门户类站点的浏览数量非常巨大，所以网站的多元化也是个很好的门路。

4.PR不是一切
PR高排名并不一定好，这是公认的，因为谷歌更倾向于相关性。所以大家优化站点时，更应更倾注精力做好内部网站的建设工作，同时适当寻找合适的外部链接和提交DMOZ yahoo等目录。