The early critics called them all fads — blogging, social networking, twittering. But the growing collection of online services that allow people to create and publish web content and connect with each other in new ways over the Internet, known collectively as social media, is changing the way we consume information and entertainment, market goods and services, and connect with friends, family, and co-workers. It's a radical departure from traditional mass media and is turning a passive audience into a throng of active participants.