Mobile community Limbo announced that it has exceeded 2 million opted-in members.

Every 12 seconds, Limbo claims to add a new member to its community. Since the launch of its iPhone application, Limbo now boasts an estimated 44 million text messages were generated in June, averaging 1.5 messages per second.

"The vast majority of traffic to our mobile Web and online site is generated by viral activities, members telling their friends about Limbo," said Dave Limp, chief operating officer of Limbo, Burlingame, CA. "Word of mouth is also driving the quick uptake of our new iPhone application as well.

"We also get significant traffic from our carrier partners," he said. "We are partnering with most of the major carriers in one form or another including Verizon, Sprint and Alltel."

Since 2005, the free mobile site has been offering games, text message alerts and mobile community interaction to members.

Limbo claims to reach more than 5 million users each month via their mobile devices with text messages and mobile Web, which is roughly 30 percent of Limbo's members.

Earlier this month, Limbo added location features to its social networking tools, so members can now display what activity they are doing, where they are, and who they're with via the mobile phone applications, text messages, Internet or mobile Web.

In addition, Limbo also launched a group messaging tool which enables members to send an interactive SMS message to multiple friends, who may then reply to the entire group.

Limbo's services are available to all members of any carrier or mobile phone model.

Both the mobile, Web and SMS, traffic and web traffic are ad-supported. Recent campaigns have included Cooking.com, Nokia, Verizon and Sega.

Mr. Limp also said that Limbo is unusual for a mobile company in that it has a broad appeal across the country and is not just concentrated to large cities on the coasts. The company's membership reaches a broad range of age groups but the sweet spot is 18-28-years-old.

"We are constantly adding new features to the service," Mr. Limp said. "Our newest addition was the location-based social applications, Who, What, Where and Shout.

"These have been very well-received and have increased our growth rates substantially," he said.