Positioning of a webpage on Google SERPs for a keyword depends on relevance and reputation, also known as authority and popularity. PageRank is Google's indication of its assessment of the reputation of a webpage: It is non-keyword specific. Google uses a combination of webpage and website authority to determine the overall authority of a webpage competing for a keyword. The PageRank of the HomePage of a website is the best indication Google offers for website authority.
So, as you build a link, ask yourself, "am I doing this for the sake of my customer or as a normal marketing function?" If not, and you're buying a link, spamming blog comments, posting low-quality articles and whatnot, you risk Google penalizing you for your behavior. This could be as subtle as a drop in search ranking, or as harsh as a manual action, getting you removed from the search results altogether!
 Matteo Pasquinelli reckons the basis for the belief that PageRank has a social component lies in the idea of attention economy. With attention economy, value is placed on products that receive a greater amount of human attention and the results at the top of the PageRank garner a larger amount of focus then those on subsequent pages. The outcomes with the higher PageRank will therefore enter the human consciousness to a larger extent. These ideas can influence decision-making and the actions of the viewer have a direct relation to the PageRank. They possess a higher potential to attract a user's attention as their location increases the attention economy attached to the site. With this location they can receive more traffic and their online marketplace will have more purchases. The PageRank of these sites allow them to be trusted and they are able to parlay this trust into increased business.
A decent article which encourages discussion and healthy debate. Reading some of the comments I see it also highlights some of the misunderstandings some people (including some SEOs) have of Google PageRank. Toolbar PageRank is not the same thing as PageRank. The little green bar (Toolbar PageRank) was never a very accurate metric and told you very little about the value of any particular web page. It may have been officially killed off earlier this year, but the truth is its been dead for many years. Real PageRank on the other hand, is at the core of Google’s algorithm and remains very important.
While ordinary users were not that interested in pages' scores, SEOs of a different caliber felt that this was a great opportunity to make a difference for their customers. This obsession of SEOs with PageRank made everyone feel that this ranking signal is more or less the only important one. In spite of the fact that pages with a lower PR score can beat those with a higher score! What did we receive then, as a result?