Why i need Pagerank for my site?

It was the first question when reading a story "How making money from blogs".

From that question, I'm trying to find out more about this PageRank. After reading wiki, more or less I understand how the calculation of pagerank on a blog works.but still, the question "Why i need Pagerank for my site?" is still there.

finally at a forum I found something interesting. These are several  things that we can get if  site or blog  have a pagerank.

1. trust
A site which has a high pagerank that means the site is believed to be the source from many people. This means that concerns about the credibility of the blog.
2. position in the search
with high pagerank, google assume that site or blog  is something important, and generally be of precedence for display according owned pagerank blog.

Knowing that thing, many people are competing to raise the pagerank of a site or blog with various purposes. although ultimately all stem from one thing, money.

To have a website or blog that had a high pagerank possible to get more advertising or a particular job.

Besides selling price of a domain that has a high PageRank can be more expensive than normal, especially if the domain that contains elements of SEO.

Pagerank can not be required, because the final determinant is google. Google will hold its regular calculation of the value of your site or blog.