SAN FRANCISCO-LinkedIn's growth is now paced by new hiring solutions that surged in 2010 to become the business social network's largest and fastest growing business.
Hiring solutions help surface LinkedIn users with professional recruiters, said LinkedIn CEO Jeff Weiner at the Web 2.0 Summit here.
While he declined to say what the private company's revenues were or when the company would file an IPO, Weiner noted that ad sales and premium subscription services were also performing well among the network's 85 million users.
LinkedIn is adding a new member every second. While it took LinkedIn 477 days to add its first million users, 1 million new people joined the network in the last nine days. Over half of the 85 million users live overseas.
Co-host John Battelle asked Weiner whether he would connect the LinkedIn social graph with that of Facebook's massive base of 500 million-plus users.
While he wouldn't rule it out, Weiner said it depends on the value LinkedIn could create for members with such an integration.
He also said it would be challenging to integrate with Facebook because of the necessary walls between the personal and family context on Facebook and LinkedIn's professional users.
"We're solely focused on the professional," Weiner said. "Time and time again we hear that people want to keep, for the most part, their personal lives and professional lives separate."
He used the analogy of "keg stands," a popular college tradition in which people stand upside down and drink beer from the keg tap.
While such pictures are fairly common on Facebook, they are not on LinkedIn. That's because professionals wouldn't want to have prospective employers seeing such pictures, Weiner explained.
One reason LinkedIn might not want to bother integrating social graphs is that it doesn't need to. The company's LinkedIn Signal, which is in beta, does a decent job integrating users' Twitter and Facebook feeds into one stream on the LinkedIn network.
Weiner also said it wasn't fair to lump LinkedIn, Facebook and Twitter under the social network mantle.
He said Facebook is a social utility with social gaming; Twitter is an asymmetrical, public communication platform; LinkedIn is a professional network.
Forgive the semantic hair splitting, but social networking, whether in the case of keg stand picture sharing on Facebook and Twitter, or job opportunities on LinkedIn, is exactly what's happening.