Social media is one of the Web 2.0 core concepts. As such, understanding the concept thoroughly is one of the keys in developing a successful Web 2.0 web site.

Basically social media denotes a site that gives its users tools for interacting with each other. Thus basically any blog or wiki or photosharing system is a social media. But what about the services or sites utilizing many components of the social media concept? Such services are designed around a common interest such as travel or sports and their success depends on user community building.

Wikipedia defines social media as “an umbrella term that defines the various activities that integrate technology, social interaction, and the construction of words and pictures.” That’s quite a mouthful so let’s break down the explanation to its components. In my opinion, the three core components of social media are:

• UGC. Social media revolves around a shared social object. Jyri Engeström wrote a good summary of what makes a good social object. Users generate these objects, thus User Generated Content (UGC). Great examples of UGC-centric services are Youtube and Flickr.
• Collaboration. People collaborate and create and connect information on their common interest The social media empowers wisdom of crowds. The most prominent example is Wikipedia.
• Social graph. Social media enable users to connect to other users in order to create a social graph of their friends (e.g. Facebook), business contacts (e.g. LinkedIn) or fellow travelers (e.g. TripSay).

The best (in terms of size and growth of user base) social media services combine all of these three components.