The company says that when it launched back in 2003, it took 477 days to reach its first million member milestone. The 50th million came much easier, however, in jus 12 days.

"While 50 million is an important milestone, we’re even more excited about how our members are using the site," says LinkedIn CEO Jeff Weiner. "Around the globe, people turn to LinkedIn to create and manage their professional identities online. They reconnect with former colleagues and develop new relationships, enabling them to create and collaborate with a network of trusted individuals. Every day professionals use LinkedIn to define themselves —and their businesses — to the world."

LinkedIn says that about half of its total membership is international. It was launched as a global network to begin with. Europe makes up 11 million users, and India is the network’s fastest-growing country with 3 million users itself. The Netherlands has the highest rate of adoption per capita outside of the United States, at 30% according to Weiner.

"We’re proud to have reached this latest milestone, and we very much appreciate our members’ use of LinkedIn," he says. "However, in the context of our mission – to connect the world’s professionals to make them more productive and successful – we’re just getting started."

Earlier this month, LinkedIn launched the profile organizer, aimed at making it easier to save profiles and organize them into folders. You can also use it to take notes on contacts.

One unfortunate thing for LinkedIn is that the ever-growing networks of Facebook and Twitter seem to be invading its turf to some extent. More and more people are using those two to find jobs. That said, LinkedIn is clearly still doing quite well for itself, gaining a member a second and all.

During Weiner’s time in the President role, he has overseen all operations and played a defining role in developing and excuting the company’s strategy on a global scale.

Speaking of that global scale, LinkedIn announced this week that it was investigating ways to make LinkedIn available in more languages. Out of the users the company polled, the majority said they’d help out with this for upgraded accounts.

"Working closely with Reid and the team over the past six months exceeded all of my expectations coming into the company," says Weiner. "I couldn’t be more excited about our progress to date, and the opportunity ahead of us."

"LinkedIn was founded to harness the power of the internet to create a tool that would help individuals become more effective and successful professionals," says Hoffman. "Over the past six months, Jeff has done an exceptional job leading the company and I look forward to continuing the work that we have begun together."

Before becoming interim president at LinkedIn, Weiner held executive titles with Accel Partners and Greylock Partners. He also held leadership positions at Yahoo such as executive vice president of the company’s network division.

“The goal behind the re-org was to help us rationalize and consolidate duplicative products, create greater focus on key priorities, clarify strategic direction, and ultimately develop an environment where we could accelerate the speed and quality of our decision-making,” Weiner said in his post on the Yahoo Yodel blog.

Weiner has a number of Yahoo’s most trafficked properties under his purview: Mail, Search, Answers, and the Yahoo home page itself. If it’s facing the Internet user, it’s probably under the Network Division.

Putting them in one division may have caused some to question that move. He said in response: “The answer to that question lies no further than our mission statement: ‘To connect people to their passions, communities, and the world