Last night, the staff of PC Gamer announced that their E-Sport Game of the Year Award for 2013 goes to DOTA 2. Except the fact of being the fastest growing game in 2013, DOTA 2 was also the most played game on Steam in 2013, while also, DOTA 2's The International 2013 tournament has proved that the game has a huge potential as a spectator sport as well.
While only in December 2013, over 6,6 Million players enjoyed Valve's ARTS title, last night for example, it attracted over 609,000 players concurrently.
All these statistics are here to prove the rising popularity of DOTA 2 and can only make us think where the game is going to be next December.
More info - PC Gamer