martinibuster - 6:12 pm on Mar 14, 2010 (gmt 0)
Norvig is discussing internal PR and how it is not the entire algorithm, which is something lost on the average webmaster. Now if that's the feeling about internal PR, think of what the implications are for the simulated PR shown on the toolbar.
A common question about Yahoo rankings is why is it so different than Google. I have seen examples where thousands of low to zero pagerank links can push a site into the number one position in Google but not in Yahoo. Yahoo fairly consistently ranks high-trust TLDs but not necessarily the most relevant pages where a .com is a known authority. What is Google doing that Yahoo is not? Why does Yahoo discount low-linked sites but Google seems to give them ranking power? The reason it works, imo, is because Google is taking into account more than the backlinks of the pages that are linking to a ranked site.
Yahoo is discounting those low-PR links but Google is not. So I started thinking about why this would be so. In this particular situation, what Google seems to be taking into account is the relevance of the page (and perhaps other factors related to trust that play a different role). These web pages are mostly PR zero. So if the toolbar PR is zero but Google is ascribing ranking power to those pages to the page being linked, then the implication is there are other factors other than PageRank at work helping these sites to rank. Factors that Yahoo is not considering.
If the above is true, and I believe it to be true for several years now based on my experiences, it's time to reconsider the toolbar PR of the pages as a link-building metric and focus on other metrics related to trust and relevance. I personally feel that anyone who uses that as a metric is overlooking other more useful metrics. As Norvig states, the PR is but one of many components of the algorithm. Trust your eyes. Look at the SERPs. Ask yourself why the SERPs are not ordered in descending order by PageRank. Ask why low PR pages outrank higher PR pages about the same topic.
These ideas may be new for some in 2010, but it's actually quite old. It's 2010 but webmasters continue working like it's 2003, for instance, the belief that links from PR 4+ sites are more worthy. It's astounding that webmasters continue working in that mode. If webmasters want to get ahead, and this has been said for years and years, it's nothing new, you have to let go of the toolbar.