Ok, it works. Here's the deal. The primary goal of the comment spammers we've been plagued with of late has been to up their page visibility on webcrawlers such as Google, MSN, Alta Vista and others. They know full well they're going to get banned - often within minutes of posting - but if their post can last an hour or so they'll get a reference which ups their page relevance and gives them a free higher listing on search engines.
Or so they believe. Google and the other major search engines have implemented a new element within the <a href> tag called rel="nofollow". When a webcrawler sees that tag on a link it will disregard the link on the page and not follow it. To put it bluntly, it turns the spammer's effort into a complete waste of their time - which is only fair, they're wasting our time.
This marker will appear on all user submitted links where the user has fewer than 50 posts. Once you clear that threshhold the system will allow web-crawlers to follow your links back to your homepages.