I'm not the most gung-ho guy when it comes to quantification. If you have a business-related blog, what you should really focus on with your blog is finding out what goods and services you can provide to make your customer your champion.
However, the enterprise loves numbers and the blogosphere keeps struggling to provide them in interesting and useful ways. My former client Alec Saunders up in Ottowa has come across Alexaholic, which allows you to see Alexa charts on multiple companies simultaneously. While I've never been wild about this, I think it's a great way for competitive companies or bloggers to track how they are doing against each other over time.
