Before this month most Americans had not even heard of Twitch. A videogame-streaming company, Twitch describes itself as “the world’s leading video platform and community for gamers.” The company allows gamers to upload short videos from games, watch other users’ uploads, and chat with other gamers. Todd Spangler, at Variety.com, first reported this month that Google’s YouTube plans to purchase the streaming company for upwards of 1 billion dolla…