While LoL is by far the more popular game, I find what Valve is doing with Dota to be more interesting. They're heavily investing in the spectator portion of the sport, and it's paying off in spades. They've added in the ability to watch replays, see instant-replays during live games (especially useful when the casters miss a battle off screen), see post-battle stats, and view player analytics all in-client.

The article mentions that Riot lost money in hosting The World Championship, but during The International (the Dota 2 equivalent), Valve made over $30 million from selling interactive playbills for the tournament. Twitch has become a huge part of the events as well, but I think it's telling that Valve is strategically moving forward with trying to make viewing the game just as important as playing the game. Esports as a spectator sport is definitely going to become much bigger moving forward (LoL's World Championship already has more viewers than baseball's World Series, and in Dota 2 to win more money than a superbowl winner you'd only have to take third place in The International). I suspect that we'll see Esports taking over physical sports in terms of numbers in the next decade or so.