Wow, PTTed, that was an amazing reply, thanks!
No problem Hitler. :ertery: (sorry, I couldn't help it - that mustache and the black hair and the eyes - it just reminds me of Hitler)
Does this mean that existing PageRank toolbars don't show accurate information?
Yes. That is what it means. That page's actual PageRank could be and likely is different than what it was a couple years ago. Like I mentioned before, for many of the sites that internet marketers might try to get a link from (like link sellers), the actual PageRank of the pages they are selling links from will be equivalent to what used to be labeled as PR0.
My site still shows a 0, wheres as DA and PA are in the 20-40 range, which has been frustrating since there's been no movement in PR! Is it a good indicator that a site still has PR if they haven't been spammed and are still active?
PageRank has nothing to do with whether a site is active or not.
Most webpages on most websites flow PageRank as long as they are not nofollowed. For the most part you can just assume a page will pass some of its PageRank through a link on that page as long as there isn't a reason to think that site lost its trust from Google.
How do you lose Google's trust? -
* By getting lots of spam links pointing back at your website
* by selling links that pass PageRank,
* by linking out to bad neighborhoods,
* by allowing other people to create link spam on your site,
* by participating in link schemes, etc.
* etc.
If the site you are getting a link from does any of that or has done any of that in the past, then there is a decent chance the site isn't going to help your rankings. If it does help your rankings, it might only help for a short while until that site gets nailed. Or it is possible that the site won't get nailed and it will keep passing value to your page. You don't know.
This is why,
ideally, you want to get clean links that look natural (even if they aren't) from websites that don't engage in spam in any way.
And ideally, you want the pages you get links from to have more PageRank because it makes their links have more rank boosting power.
Certain pages on websites tend to have more PageRank to pass than other pages. An example of this would be a website's homepage or a page that is linked to directly from the homepage. Those pages typically have more PageRank just because the majority of websites out there have a link from every page on their site pointing back at their homepage. That generally causes the homepage to acquire more PageRank than other pages deeper inside the site. Some of the PageRank from every single page flows over to the homepage.
There are instances where internal pages have more PageRank than the homepage and more PageRank than the pages linked to from the homepage. I have sites like that where an inner page has the most PageRank (well at least they did back when they published PageRank numbers publicly). So if a page has lots of links to it and those links come from non-spammy sources or even if it just has one really good link pointing to it from one really good source, then that page tends to have more PageRank to push through its own links.
Hope that makes sense.