A new report from the Pew Internet and American Life Project (see full text) finds that many people use social media, but that politics is just an incidental motivation for most.
Two-thirds of online adults (66%) use social media platforms such as Facebook, Twitter, MySpace or LinkedIn. These internet users say that connections with family members and friends (both new and old) are a primary consideration in their adoption of social media tools. Roughly two thirds of social media users say that staying in touch with current friends and family members is a major reason they use these sites, while half say that connecting with old friends they've lost touch with is a major reason behind their use of these technologies.
Other factors play a much smaller role: 14% of users say that connecting around a shared hobby or interest is a major reason they use social media and 9% say that making new friends is equally important. Reading comments by public figures and finding potential romantic partners are cited as major factors by just 5% and 3% of social media users, respectively. [emphasis added]
The survey was conducted Apr. 26-May 22, 2011. Read the full report for more information about the degree to which different age and ethnic groups value social media.