I've heard of some one-off changes in Toolbar PR over the past week - including more of those silly internal grey bars. But so far no widespread reports of PR changes.

There was a fresh export of PR data to the toolbar in April 2007, so this would be the anniversary. However, it's getting hard to know when the "most recent" true PR update was, with all the games we've been seeing surrounding suspicion of link selling/buying. The traditional "pattern" was every three months, but now?

Its strange, because traffic is up significantly over the last few weeks.

Not really strange - considering that your "real"PR is continually being re-caluculated. A change on the toolbar should never coincide with change in your rankings. The rankings already change long before the toolbar PR. And even more, PR is just part of the "query-independent" part of the algo. The query dependent parts have a lot of punch so lower PR doesn't necessarily mean lower traffic.

So two months ago, I discovered a major SEO problem ... the site didn't have any META tags after a cosmetic redesign. It apparently had been that way since last Sept, when the work was done)... I put them back in ... is it possible that the lower PR is a result of the toolbar catching up to a previous downgrading because of the missing META? (its fixed now).

The PR equation is calculated via backlinks. That operation has nothing to do with any other factors.

However, Google may also re-evaluate backlinks, even if they continue to exist, and decide not to let some of them "pass PR" even if they used to.

My established 7 year old site has drop a massive 2 PR points across all pages. Anyone?

[edited by: tedster at 11:51 pm (utc) on April 15, 2008]
[edit reason] moved from another location [/edit]

jretzer - Not the Meta however I do feel the PR update is based on old calculations made a a few months back.

For what it's worth I'm seeing a TBPR update.

It's kinda helpful to see our deep pages are at least counting for something, more than they did 3 months ago.

PR is not only calculated on backlinks.
The quality of the site is one major determining factor. If your site is not kept up to date then you will find that it will loose its quality. I have seen many high PR sites go down over time as they just dont update the site. Its good to see as it kills out the competitors who dont keep their sites fresh.

PR is not only calculated on backlinks.

No, PR is calculated only on backlinks. However, some backlinks can be de-valued or sometimes even ignored.

The quality of the site is one major determining factor. If your site is not kept up to date then you will find that it will loose its quality.

Quality is one of the factors used, with different metrics used for evaluating the quality of site, but quality isn't a PR related factor, which is a separate issue.

I have seen many high PR sites go down over time as they just dont update the site.

That going down isn't related to updating freshness; because a site can retain healthy PR without being updated for a long, long time. However: not having new backlinks for a long time, or old backlinks that are "stale" can cause a PR drop because the old links lose value.

PR0 & Historical Factors:

[webmasterworld.com...]

And there's a link to the patent in that thread that goes into the various freshness factors looked at.

...However, some backlinks can be de-valued or sometimes even ignored.

Bingo. But seriously, I wouldn't put too much emphasis on Page Rank. It's only one drop in a growing pool of ways to encourage the sale of a website.

Much ado about nothing, PR is insignificant.

Much ado about nothing, PR is insignificant.

I would disagree with this statement.

I firmly believe that PR is a factor in G-Bot speed, frequency and depth.

It is also a major (READ HERE: NOT MINOR) factor in removing pages from the (yes, it still exist) supplemental index.

I don't know about PR being a factor in removing pages from supplemental, however, I've got a low PR website that gets crawled by Googlebot on an almost regular basis and performs quite well in producing organic traffic.

I've also got high PR sites than see the opposite behaviour from Googlebot.

PR is significant. Toolbar PR is insignificant.

Can we put this one to bed once and for all.

I think most if not all of the relevant points about PR are in this thread in our Hot Topics [webmasterworld.com]:

2008 - Does Google PR still matter? [webmasterworld.com]