Dota 2 makes $18M per month for Valve — but League of Legends makes that much every 5 days

The most-played game on Steam is free, but that doesn’t mean it isn’t making Valve a ton of money.

Dota 2 is a growing force in the multiplayer online arena battler space. It makes $18 million every month, according to industry-intelligence firm SuperData Research. And that number is on the rise as Valve’s highly competitive game attracts new players and helps the company capture a bigger piece of the MOBA market, which is about $54 million a month in the United States alone.