PR of the linking page is more important than the PR of the linking domain. This is because your site will get the PR of linking page and not that of the root domain. Even if the linking page has no PR it can still be targeted provided it is frequently crawled and indexed.
http://forums.seochat.com/google-optimization-7/assessing-the-pr-of-a-backlink-286523.html
In an SEO Monopoly a company is attempting to control multiple sites on the front page of the search results. Each of these sites have some way of highlighting the parent company, usually, through the form of posts or text ads.
