How do you build a gigantic prize pool for your e-sport? You get the community evolved.

The International is a huge tournament for Valve’s Dota 2, a competitive multiplayer online battle arena game. It’s one of the most popular games for spectators, and those fans are happy to help contribute to The International 2015’s prize pool before the event starts on July 3 in Seattle. To do so, they just have to buy something called the Compendium, either in a $10 package or a $27 one. Doing so will give them access to in-game rewards, with more unlocking as more is donated. Just 25 percent of Compendium sales go toward the prize pool, but it’s already raised a good chunk of change.

Last year’s Compendium helped create a staggering $10,930,698 prize pool for The International 2014. This year’s effort has already raised $1,917,155. That’s nearly¬†as much as the $2 million that Dota 2 competitor League of Legends uses as the prize pool for its championships. That’s despite League of Legends having more players than Dota 2. However, League developer Riot Games won’t ask players and fans to help fund its prize pool, feeling that it should be the company’s responsibility.

Still, both games are helping the e-sports scene grow rapidly. E-sports games made $194 million in revenue in 2014 and could make $465 million in revenue in 2017, according to a report from research firm Newzoo.