Da ComScore.com:

A study announced today by GroupM Search, comScore and M80, exploring the interplay of search marketing and social media, reveals the dramatic correlation influenced discovery of brands through social media has with search behavior, including more lower-funnel searches and increased paid search click-through-rates (CTR).
The study,“The Influenced: Social Media, Search and the Interplay of Consideration and Consumption,” explored the correlation between social media exposure and search behavior across different verticals, including automotive, consumer packaged goods and telecommunications.