Spectators for video games?

NS about the notion of spectator in gaming:

he US professional computer gaming league has just signed a TV rights deal with cable company USA Network. Maybe it could be on the way to becoming as popular a specator sport as football and basketball in the US.

Why do I blog this? this is connected to my interest towards user experience of video games: there is really a trend that gaming is more than just interacting with a box: now with replay (in sport games for instance: you can replay your own game) and here with this trend it's more than that: showing to others people's game. I'd be interested to know more about who watch this, what they do out of it... and the practices related to that.