Social giants like Facebook and Twitter might have it beat, but marketers shouldn’t count LinkedIn out just yet. The professional social network announced today that it had passed an important milestone: 200 million members.

Launched in 2003, LinkedIn’s growth rate really accelerated through 2012, adding more than 13 million members since November. For comparison’s sake, memberships stood at 32 million in January 2009.

According to LinkedIn, its network of professionals come from 200 countries and use the site in 19 different languages. In fact, more than half of all LinkedIn members live outside the U.S. — that’s a pretty varied target audience. International growth is especially important, with Turkey and Colombia leading the fastest growing countries.

What contributed to LinkedIn’s growth? In 2012 alone, LinkedIn launched an iPad app, introduced an influencer network, and redesigned profiles and Company Pages. Revamping a design can really breathe new life into a community, but we like to think that smaller features, like endorsements, also helped to pull in members.

While 200 million (registered members) is still a far cry from Facebook’s 1 billion, it’s an impressive feat for a network that focuses on relationships more than broadcast marketing. If your company still doesn’t have a presence on LinkedIn, now is the time to create one.

[Via: VentureBeat, Image credit: Nan Palmero]