Raptr has more than a million users of its gamer social network, which has been in testing for more than two years. So now is as good a time as any to formally launch the company’s platform.

Dennis Fong, chief executive of the Mountain View, Calif.-based company, said in an interview that the platform is stable enough and growing fast enough to declare version 1.0 ready.

But he still doesn’t have a business model. That can come later, after the company grows to something like 20 million users or so, Fong said.

The company is still testing business ideas, such as getting referral fees when it signs up gamers for free-to-play online games. And there is advertising targeted at gamers as well. But for now, Fong is concentrated on getting more users. The company currently is adding users at a rate of 500,000 per month, or 15,000 to 20,000 per day — without advertising.

Fong said that the growth in users took off when the company added the ability to keep track of what your friends are doing, whether or not they are signed up as members of Raptr. The platform can automatically import your friendlists so that it’s easier for you to keep track of them and thereby invite them into multiplayer online games.

The lack of a business model may sound very “dotcom,” but Fong knows what he’s doing. He was formerly known as “Thresh” or the Michael Jordan of professional video game tournament players. He fragged endless numbers of enemies in games such as Doom and Quake. He won a Ferrari, and then he became an entrepreneur. He’s on his third game-related startup (though his first, GX Media, is the parent of three game firms: Gamers.com, Firing Squad, and Lithium Technologies). The last one, his rival Xfire, was bought for $102 million by MTV.

At Raptr, Fong’s team of about 30 has built a loyal audience. They provide instant chat service and a full-fledged social network so that gamers can find their friends and play games with them. The platform is agnostic, pulling a gamer’s data from the PC, PlayStation Network, Xbox 360, Valve’s Steam network, and the Xfire gamer chat service. Users can engage in chat with others on any platform, with the exception of the PlayStation Network. Right now, on PC games, you can chat with your friends using Raptr from inside any game in progress.

“We’ve built the ultimate gaming buddy list,” Fong said.

The company started in 2007 and has been trying out features for some time. It raised $12 million in financing from Accel Partners and the Founders Fund. It still has money in the bank. Fong says he has a low burn rate and doesn’t need more funding at the moment.

The company has been able to collect considerable data about what games are popular based on how long its members spend playing the titles. Raptr shares statistical, anonymous data with game web sites such as GamePro and GameSpot, which use the data to show gamers how popular games are and what they should buy. Raptr knows that most gamers are multiplatform players now, playing FarmVille one minute and Call of Duty Modern Warfare 2 the next.

“When I saw six of my friends playing Red Dead Redemption, I knew it would be a hot game,” Fong said. The next big game that Fong foresees making a splash is Starcraft II, which debuts on the PC on July 27.

Other gamer social networks have come and gone. GamerDNA is dormant, as is MyGameMug. Rupture, which was started by Shawn Fanning and purchased by Electronic Arts, has been shelved. A variety of others made some noise and disappeared. There are still competitors such as IGN.com, which is making its game fan sites more and more social. But Fong expects his company will be able to partner with companies that either have a lot of game fans or game buyers.

Since the game web sites have so many users, Raptr gets a continuous stream of new users. If growth continues at the current rate, Raptr could have 6 million users by year end. And by then, Fong will be thinking seriously about his business model. There are plenty of chances to do money-making partnerships with game sellers, game distribution networks such as Gaikai, or game fan sites.

“In a year or two, we see ourselves as the Facebook of games,” Fong said.