INteresting article on the cost of google+ and Facebook. Never realized how a slight delay in page load can cost a lot of ROMI. This is an unseen cost of social media.
Interesting article. What's missing is the cost of an unsubscribe or an email junk mail designation (by the user). These costs though have more to do with the email marketing, then the address, but are nevertheless expensive.
Great article from Michael Wolfe. He is definitely one of the world's best marketing measurement gurus. Worth a look on how he is measuring the impact of social media.