More than 21 million gaming fans tuned in to Twitch during the Electronic Entertainment Expo, nearly twice as many viewers as the year before. Concurrent viewership peaked at 840,000, according to Amazon-owned Twitch. The streaming site’s coverage included live press events and action from the Los Angeles Convention Center showroom floor. Roughly 1,800 streamers provided their own commentary, the first time Twitch allowed them to do so from its E3 channel. “Last year, Twitch became the fourth-largest source of U.S. Internet traffic, trailing Netflix, Google and Apple, according to research firm DeepField,” The Wall Street Journal reports.