Pagerank is basically generic authority / ranking power and it is gradually declining in significance as bounce rate analysis is improving, but links still have a significant impact on rankings and that’s mostly due to pagerank. However it is also due to transfer of keyword relevance (which is weighted by pagerank).
Something to note is people in the white-hat scene, especially big brands with a reputation to consider, usually snarl at the idea of pagerank sculpting, because Google advises to focus on users rather than robots, and it’s kind of a grey hat tactic, but Google says a lot of things to deter non white hat SEO – this doesn’t mean only white hat works though; and Google even includes a pagerank sculpting feature within it’s heavily promoted sitemaps technology. The idea of being user-focused vs robots-focused is a good one for white hat sites but the ultimate approach is to consider users and robots as one, and account crawler flow in the same way as we account for user flow around our site. If the content is important both crawlers and humans should be exposed to it fast, and if it’s trivial the back pages is a good place for it.