Based on publicly available data, it looks like an Internet milestone will be passed by the end of next month: World of Warcraft will lose its undisputed status as the most popular massively multiplayer online world. It’s struggling to defend that title as Habbo Hotel, the web-based, social MMO from Finland’s Sulake Corp., is nipping at its heels. Habbo just sent me news that it has logged its 100 millionth registered avatar (pictured at left), and more crucial, that Habbo “attracts close to 10 million monthly visitors to its services worldwide.”

Currently 9.5 million active monthly users, to be exact, compared to Warcraft’s last-reported 10 million subscribers — but at current growth rates, it’s easily within striking range.

“Habbo expects to exceed 10 million unique monthly users within the next 30 days given current growth rates in Habbo and in virtual worlds as a whole,” Habbo Executive Vice President Teemu Huuhtanen told me through a publicist. (In the last six months, the company reports adding 20 million new avatars through a major site redesign and waves of new content, including avatar-based celebrity appearances by “American Idol”’s Jordin Sparks and others.)

“The users want to focus on Habbo’s core,” explained Huuhtanen. “[T]hat is, being in the [virtual] hotel — as opposed to extraneous material on the home page.”

Of course, the battle may not be over: Blizzard/Vivendi might have added more subscribers since reaching 10 million last January, so stand by for updates. Meantime, check out my write-up on “The How of Habbo Hotel,” in which a Sulake executive explains how it gained Warcraft-level numbers with a much smaller budget.

Image credit: www.habbo.com. LOL embellishment by WJA.