According to a comment in DigitalPoint forum, PR updates constantly. We only get shown an estimate of PR across the last 3 months. So a week after the update, your PR is useless but it wont be the end of link sales. It only takes longer to value links.
http://forums.digitalpoint.com/showthread.php?t=1557979
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.
