Blizzard as announced in a press release that Starcraft II: Heart of the Swarm, which was in development for the past 2 1/2 years, sold 1.1M copies in its first 48 hours.
In addition, 1.1M viewers also tuned in on launch to watch live streamed launch events, with peak concurrent users of over 125,000, according to live steam service Twitch.
1.1M seems to be an important number, because that many viewers also tuned in to watch the Heart of the Swarm Major League Gaming Winter Championship tournament based out of Dallas. The MLB tourney had a peak concurrent viewership of over 157,000 users.
Starcraft II: Heart of the Swarm was released on the 12th March 2013 and earned a rave 9.5/10 score from Strategy Informer's .