One challenge is that some of the metrics are less objective than one might think. Click-through rates are calculated differently so that, depending on which service you use -- bit.ly or Tweetburner -- are vastly different. However they capture data about click-throughs, their results are like apples to oranges. Meanwhile, there are plenty of tools to track how many visitors go to your blog or site, and no two provide the same number. In fact, I've seen data from one site tool that provides different results for the same site.
That, of course, makes selling in social media programs a bit of a challenge.
But in reading Charlene Li's new book, Open Leadership, I came across a useful quote. Li is the founder of the Altimeter Group and a former Yankee Group analyst. According to Li,
"Inevitably they (management) want to know what the return on investment (ROI) is. But this emphasis on ROI is like asking what the value of a deeper, closer relationship is. Although I agree that leadership should rigorously examine the benefits of openess, an undue emphasis on hard ROI does no one any good...The challenge is getting the right people within the organization to understand that social media is another means by which they can connect to key audiences. Even B2B companies need to consider connecting with their customers because so many of them are using social media anyway.
For example, what's the ROI of a handshake? Or think of a lunch you recently had with a colleague or direct report, where you invested time and money to develop a deeper relationship with them. How do you calculate the ROI of an internal business lunch? ...In most cases, more than half of a company's operating expenses are likely to be spent on activities that have an indirect impact on the bottom line. We may not be able to link the ROI of these expenses to direct sales, but we know there's some incremental benefit that makes them worthwhile."
(Disclosure: I received a review copy of "Open Leadership.")