Google might see 10 links on a page that has $10 of PageRank to spend. It might notice that 5 of those links are navigational elements that occur a lot throughout the site and decide they should only get 50 cents each. It might decide 5 of those links are in editorial copy and so are worthy of getting more. Maybe 3 of them get $2 each and 2 others get $1.50 each, because of where they appear in the copy, if they’re bolded or any of a number of other factors you don’t disclose.

As of 2009, there are only a few large markets where Google is not the leading search engine. In most cases, when Google is not leading in a given market, it is lagging behind a local player. The most notable example markets are China, Japan, South Korea, Russia and the Czech Republic where respectively Baidu, Yahoo! Japan, Naver, Yandex and Seznam are market leaders.
Cause if I do that, If I write good content, whilst my 100+ competitors link build, article market, forum comment, social bookmark, release viral videos, buy links, I’ll end up the very bottom of the pile, great content or not and really I am just as well taking my chances pulling off every sneaky trick in the book to get my site top because, everyone does it anyway and if I don’t what do have to lose?
PageRank is a link analysis algorithm and it assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. The algorithm may be applied to any collection of entities with reciprocal quotations and references. The numerical weight that it assigns to any given element E is referred to as the PageRank of E and denoted by {\displaystyle PR(E).} Other factors like Author Rank can contribute to the importance of an entity.
Meanwhile, the link spam began. People chasing higher PageRank scores began dropping links wherever they could, including into blog posts and forums. Eventually, it became such an issue that demands were raised that Google itself should do something about it. Google did in 2005, getting behind the nofollow tag, a way to prevent links from passing along PageRank credit.

Your social media strategy is more than just a Facebook profile or Twitter feed. When executed correctly, social media is a powerful customer engagement engine and web traffic driver. It’s easy to get sucked into the hype and create profiles on every single social site. This is the wrong approach. What you should do instead is to focus on a few key channels where your brand is most likely to reach key customers and prospects. This chapter will teach you how to make that judgment call.
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? 

Page Rank