Social media comes to health care

What makes a social network valuable ? Facebook (FB), with more than 1 billion active monthly users posting photos, sending messages, and updating their status, has an impressive market capitalization of $65 billion, or about $65 per user. But Wall Street has assigned a valuation of almost $18.5 billion, or $92.50 per user, to LinkedIn (LNKD), the professional networking site that offers its 200 million members arguably more crucial services, such as help finding jobs. Now a cadre of social platforms aims to disrupt the way consumers share information about personal health, physicians, and treatments. Despite a proliferation of apps that let people monitor every movement and morsel they eat, information technology has yet to revolutionize health care the way it has upended, say, shopping. What the upstarts lack in scale (for now), they more than make up for in utility. Imagine joining an online global community of people with the same rare disorder, or finding a doctor on the basis of detailed patient reviews. Facebook may provide its fans with tools they love, but this new wave of social networks offers tools that its users can't live without -- in some cases literally.