Twitch is little short of a phenomenon - now a household name for videogamers. The site attracts 60 million enthusiasts each month to watch live and on-demand streams of other players' efforts. In the three years since it was born as an offshoot of the general video-streaming site Justin.tv, it has also become the de facto home for e-sports competitions in the US. It now consumes more primetime internet traffic in the US ...