Amazon is buying Video Game Live-Streaming Site Twitch for $970m in cash, to get into one of the fastest-growing online arenas: live-streaming video, Reuters has reported. Live streaming draws a following partly because of its immediacy: fans message their favorite personalities and can evoke a response during livecasts. Twitch and other live-stream networks such as Livestream also cater to niches, featuring content such as offbeat sports to videogames that mainstream outlets eschew. Twitch had 55 million monthly viewers in July, up about 45 percent from a year earlier. That growth caught the attention of advertisers, who spotted the chance to reach younger viewers who watch less television.