Social Media is a Game?

Watch the last 5 Minutes of Charlie Brooker's How Videogames Changed the World and you will find that the argument arises that social media such as Twitter and Facebook are now considered as games.

The idea that is presented mirrors that of Danah Boyd:

“As we Twitter our way to friendship, scoring ourselves based on the numbers of 'friends' we can convince to subscribe to our existence, perhaps we lose track of what friendship and connection mean.” 

What do you think? Are we "playing" a game online? Are you yourself online or offline or both? In fact who are you really?