That 1 million figure is a combined efforts of those watching via Twitch, Gamefy in China, and through Valve's services such as those watching within Dota 2's spectator mode. Those figures do not include those who watched via international television broadcasts, nor those in attendance at the Pubstomp viewing events that were held in over 40 countries around the world.
The International was launched two years ago in Cologne, Germany during Gamescom with 16 of the most elite Dota 2 teams competing in a group stage, double elimination playoff format for a grand prize of $1 million.
For the first time, this year's prize pool was bolstered beyond Valve's contribution by Dota 2 player participation in the Interactive Compendium. With the community's involvement in the Compendium, the total prize pool was pushed from $1.6 million to over $2.8 million.
For the first time, this year's prize pool was bolstered beyond Valve's contribution by Dota 2 player participation in the Interactive Compendium. With the community's involvement in the Compendium, the total prize pool was pushed from $1.6 million to over $2.8 million.
Again, this was just during the peak viewship moment during the tournament. There were undoubtedly countless others who tuned in at various other points to watch some of the festivities online that may not have been there during the peak moment.
Don't forget that Dota 2 is a free-to-play title from Valve. You can get a complete recap of what happened last week during The International 2013 by heading on over to the Dota 2 website.