For the most part, Page Rank is obsolete. While the model of link authority distribution where links pass a portion of a page's PR may well be reality, the value of this number is highly questionable and overly simplistic. Our test suggest that the number may actually be rounded from a more precise value. Others suggest that the value given is intentionally old - the PR adjustments only happen once every 3 months or so. In any case, it doesn't address actual search considerations, it's only a measure of link juice.
So where's the deception?
Remember back when Google was talking about democratizing the web and how their goal was a natural search result that would not be influenced by money? Part of the deception is in that stated goal.
Those of us who work on many large sites know that there have been, up to 2008, 2 very distinct methods for pushing sites. Of course there are an infinite number of individual techniques that work. What I mean is that there are 2 category level rank pushing techniques: -1- develop links and -2- develop content. And at the highest levels, these 2 items are still the focus of development as with any small site.
Because we have seen, and continue to see large risks in link development, our clients were not big link buyers, and instead developed structural strength around well researched keyword universes. That is, building genuine relevancy into organizational structure. Large, semantically driven content sets focused on valuable targets can be extremely effective. And is very safe, with no effort to influence PR, only relevancy.
But up until very recently, link development meant link purchasing (now considered a black hat strategy), and what many assumed they were really buying was PR, sent across the purchased links. By focusing on PR the link buyers were really creating an environment that would eventually self destruct. See the link authority trainwreck.