Valve finally has as many players for its latest big hit as the long-running World of Warcraft … the only difference is that Valve’s game is free.

In the last month, the free-to-play Dota 2 has had 7.86 million players, according to Valve. That’s a huge milestone, as it means Valve’s multiplayer online battle arena game (MOBA) has surpassed Blizzard’s flagship. That massively multiplayer online hit currently has 7.8 million monthly active subscribers, according to the publisher’s last announcement. Of course, “subscribers” is very different from “players” as World of Warcraft still charges a $15 monthly fee to each of those players where Dota 2 is free with microtransactions. So while Dota 2’s popularity is on the rise, these numbers might reveal more about the long-lasting success of World of Warcraft than anything else.

A more apt comparison for Dota 2 is League of Legends from developer Riot Games. Both are free-to-play MOBAs with a focus on competitive play. League of Legends debuted in 2009, which gave it a four-year headstart on Dota 2, which released in 2013. Riot was able to turn that advantage into nearly 67 million monthly active players, according to the company. The action-strategy title dominates market share both in terms of the number of people playing as well as spending.

In 2013, Dota 2 made a respectable $80 million in microtransaction sales. That includes selling in-game goods and character customizations. That enough to make it the 13th highest-grossing online PC game worldwide last year, according to industry-tracking firm SupderData Research. That’s only a fraction of the revenues that League of Legends produced over the same time frame.

According to SuperData, League of Legends made $624 million last year from its millions of players around the world. That made it second behind only the Chinese first-person shooter CrossFire, which made $957 million.

Interestingly, World of Warcraft, which makes the bulk of its money from the aforementioned 7.8 million subscribers, made an additional $213 million from in-game purchases. So while Dota 2 is growing, it still has plenty to aim for.

In 2014, SuperData analyst Joost Van Dreunen expects Dota 2 to grow exponentially.

“I anticipate Dota 2′s success will continue in 2014,” he told GamesBeat earlier this year. “Over the course of 2013, Dota 2 managed to triple monthly revenues. Considering the current momentum behind the MOBA category, we expect it to double monthly earnings by the end of 2014.”

Dota 2 Diretide Trailer