A report out on why social media can't tell you who your customers are was revealing. I use social media to find product reviews and opinions. It can provide some real gems of info.
However, the report said that "the social media audience comprises three distinct kinds of social media users: enthusiasts (those who post 5x/week or more), dabblers (post 2 to 4 times per week) and lurkers (who post once a week or less).
About 90% of the 'noise' that comes from social media is from 29% of the social media audience. Just because social media consumers aren't posting, doesn't mean they aren't noticing what is being said. Lurkers make a big proportion of those who visit their Facebook page daily but don't comment, so marketers can't be sure that those enthusiasts who post are indicative of their customer base.