Bob Hoffman:

“Extensive new research” from a firm called EngagementLabs throws about an ocean of cold water on this belief.
 Here’s what they did. Over the course of a year, they did a week-by-week study comparing online chatter with real talk – “the conversations people have in person with family, friends, colleagues at work” – for 500 brands.
 They measured four parameters: Volume (the amount of talk); Net sentiment (positive talk minus negative talk; Sharing of content, and Influence (do the people who chatter matter?)
 Here’s what they found.
 For volume “the findings were mixed… But for all practical purposes, the association was not sufficient that a brand marketer could reasonably assume that one is a mirror to the other.”
 For sentiment, “no meaningful correlation at all.”
 For sharing “…the correlation for brand sharing was essentially zero…it is fair to conclude that consumer engagement with brands’ marketing content works entirely independently offline and online.”
 And finally, the affect on more influential consumers? “On this metric there is a slightly negative correlation.” In other words, the more online, the less real-world.
 While positive word-of-mouth is a valuable asset to marketers, this study is pretty damaging to the theory that social media is related to real-world word-of-mouth.
 Like so many other social media fantasies, the idea that social media chatter is the “tip of the iceberg” of consumer interest is turning out to be another marketing delusion.