Is the Google's PageRank algorithm a secret?

Which are the elements that mostly characterize Pagerank? In addition, how do social activities contribute to its development? Is there any connection between the social media activities and the algorithm that defines Pagerank?

• Answer:

  Google and Bing both recently admitted that Twitter and Facebook are considered in the algorithm. So, there's not only precedence, but admission from the search engines that social media matters. As far as "characterize Pagerank", I assume you mean which factors influence or contribute to PR. There are over 200 different metrics that ranking is measured by, and these change on a continuous basis. Additionally, no one knows the entire gamut of what's considered in the ranking algorithm. There are many good documents on SEO best practices (one is from Google itself), and reading/implementing these guides will get you off to a good start in high rankings.