I am measuring a PR and Social Campaign right now! And I liked this article by David Berkowitz on how to do it.You can access all the data and articles, and believe me, you will want to do it, but these are the few comments from other coleagues that really caught my attention:
* Buzz is really shorthand for the number of mentions of a brand or topic. And I like to use buzz broadly sometimes to denote chatter across forums, blogs, Twitter, social networks, etc.
* If used appropriately I've seen companies reduce budget significantly by cutting out a previous spend due to the great functionality enabled by social.
* The migration of folks that were once offline and are now online specifically because of your online engagement.
* Web analytics guarantee marketers are immediately and unequivocally accountable for the strategies they recommend and promote
And this is a great video (rather old maybe now, but powerful though) which in a few seconds shows the power of socialnomics.