If you’re a teen, chances are you’ve checked into the Habbo Hotel. Sulake, the parent company of the cartoon-style virtual world, said today that more than 200 million people have registered as users for Habbo.

That means they’ve created a virtual character called a Habbo. The virtual community is more than 10 years old. It started in Finland and has now grown to more than 150 countries. While traffic to virtual worlds has waned in the age of Facebook and the iPhone, Habbo’s numbers show it has fared well and is growing quickly. It shows that once a community hits critical mass, its growth can accelerate.

On a monthly basis, Habbo gets more than 13 million unique visitors a month. In the U.S., Habbo hasn’t done as well, hitting 1.5 million visitors a month. But during the holidays, U.S. usage swarmed to 3 million. Sulake announced that it hit its first 100 million registrations in June 2008. Hitting 200 million so soon after that shows that growth has accelerated in the past 2.5 years. Sulake adjusted to the popularity of social networks by creating its own Facebook application, which gets more than 2.6 million monthly active users, or more than a quarter of the active users.

In 2010, 42 million registered characters logged in. Those characters spent more than 400 million hours in the community during the year. I met Timo Soininen, chief executive of Sulake, last week in Germany. He said that adding new features and making quick changes has helped the company keep up with users’ needs and tastes.

Back in December, Sulake said that Habbo’s user revenue from virtual goods sales hit $6 million, its highest month ever. Revenue in 2010 grew 25 percent compared to 2009. Roughly 51 percent of the users are 13 years to 17 years old. About 16.5 million users spent more than 10 hours in Habbo during the year. An average paying user spent 93 hours in the world. Rivals include Gaia Online, Second Life and other virtual worlds.