Lots of times the PageRank of a domain is not it’s true PageRank. Rather, it is the PageRank of a domain that is the result of a 301 redirect.
This can be a black-hat technique. Someone could assume a high PageRank through a redirection and then offer link exchanges to have their link added to real PageRank sites. To make this method even more effective, one could perform the redirect only when a google bot is detected and display their own content otherwise. This is known as cloaking. There are other types of cloaking as well.
I have added a page to this site to assist in determining whether the PR of a site is authentic or not. It’s pretty straightforward: PageRank Authentication
[…] perform an info search in google (ex. info:domainyank.com). As I have said before, you can easily spoof a page rank by performing a simple redirect to a site with a high page rank. Google’s info search will […]
Pingback by Expired Domains with Rank - DomainYank » Google Info Domain Authenticity — November 21, 2007 @ 6:43 am