The Google toolbar
If you have the Google toolbar installed in your browser, you will be used to seeing each page's PageRank as you browse the web. But all isn't always as it seems. Many pages that Google displays the PageRank for haven't been indexed in Google and certainly don't have any PageRank in their own right. What is happening is that one or more pages on the site have been indexed and a PageRank has been calculated. The PageRank figure for the site's pages that haven't been indexed is allocated on the fly - just for your toolbar. The PageRank itself doesn't exist.

It's important to know this so that you can avoid exchanging links with pages that really don't have any PageRank of their own. Before making exchanges, search for the page on Google to make sure that it is indexed.

Sub-directories
Some people believe that Google drops a page's PageRank by a value of 1 for each sub-directory level below the root directory. E.g. if the value of pages in the root directory is generally around 4, then pages in the next directory level down will be generally around 3, and so on down the levels. Other people (including me) don't accept that at all. Either way, because some spiders tend to avoid deep sub-directories, it is generally considered to be beneficial to keep directory structures shallow (directories one or two levels below the root).

ODP and Yahoo!
It used to be thought that Google gave a Pagerank boost to sites that are listed in the Yahoo! and ODP (a.k.a. DMOZ) directories, but these days general opinion is that they don't. There is certainly a PageRank gain for sites that are listed in those directories, but the reason for it is now thought to be this:-

Google spiders the directories just like any other site and their pages have decent PageRank and so they are good inbound links to have. In the case of the ODP, Google's directory is a copy of the ODP directory. Each time that sites are added and dropped from the ODP, they are added and dropped from Google's directory when they next update it. The entry in Google's directory is yet another good, PageRank boosting, inbound link. Also, the ODP data is used for searches on a myriad of websites - more inbound links!

Listings in the ODP are free but, because sites are reviewed by hand, it can take quite a long time to get in. The sooner a working site is submitted, the better.

by Phil Craven  http://www.webworkshop.net