When I first started this some years ago. I use to think that PR or pagerank was the do all and end all of SEO. The first thing I would look at when deciding to link to a website was PR. After years of trial and error, I have personally experience just how much and how little PR really means. Firstly, PR was named after some guy in google who created it. Larry Page. He decided to give websites a rank based on how many website are linking to it. Think of a incoming link to your website as a vote for your website. But again, its not that simple. These "votes" need to come from relevant and trusted sources. If a gardening website linked to a sports supply shop - even if both websites already have high position in the SERPs. It would not be counted. You have to be smart with your links. I read on a blog some time back about job openings for Link Ninjas. I think that is a cool way of calling the job. Think of all the ohhs and ahhs when introducing yourself in a bar....