I did not know my Google PageRank until Phil mentioned it to me a while back. Apparently it's like the Richter (not Jeffrey Richter) scale in that a Page Rank of 6 is 10 times "better" than a Page Rank of 5, if I understand correctly.
Someone approached me to do advertising on the site, and since the bandwidth bill is due, I quoted a price I though was reasonable. She said, "but you only have a Page Rank of 5." This, for a moment, I become aware of this number since this advertiser cared.
I looked in the Google Toolbar and saw this:
Ok, looks like my Page Rank is 5, seems reasonable. However, later I noticed that if I was at http://www.hanselman.com/blog/ (note the lack of default.aspx) the Page Rank was 6. Seems like even though the home page is the home page, if there's a default.aspx at the end, that's a less "powerful" page.
I can only assume that more folks link to http://www.hanselman.com/blog than to the page with default.aspx. Apparently 10 times more, which seems reasonable.
I mentioned this to Phil who said, "weird, let me try" and sent me this screenshot where his Toolbar says my page is a 7. If I understand it, that's 100 times more shiny than a 5. Or, just +2. Who knows.
if Google's PageRank system is this subtle, and URIs aren't well canonicalized in their system then what's the point, Dear Reader? I know not. Seems like voodoo to me.
UPDATE: This post on the WebMaster group in response to another user says:
The page rank you see is not the pagerank Google uses.
- The pagerank you see is exported 3-4x/year
- It is "guessed" at whenever the page did not have a pagerank back
then. So if you have a "toolbar pagerank" (the one you see) TBPR 3 for
your homepage, and add a new sub-page, it will guess your sub-page to
be (perhaps) PR2, even though it doesn't have a real value for it yet.
- It is page-based ("page" rank :-)), not domain / site based
- Your sites internal interlinking structures determine how pagerank is
distributed among the pages - in the simplistic example where you have
a single page with is fed with pagerank (from the outside), you could
determine how that pagerank is spread among your pages based on the
link-structure in your site. You'll likely just give up if you have
more than 5 pages though :-) - it's not worth it.
- Your example with the homepage with a high PR and the other pages
having lower PR is perfectly normal and could be a "steady state"