This is pretty interesting - there are a large number of 'social media monitoring' products around (I work on one), and it looks like Google intend to provide their own here.<p>To get around the privacy issues with indexing private user data, it looks like they're going for an 'opt-in' model whereby social networks offer to feed data to Google, though it's not clear to me what the benefit(s) for the social network providers will be.<p>Google Analytics is already a priceless tool for measuring marketing effectiveness, and it makes a lot of sense for Google to bundle social media effectiveness in there too.