"There's a lot more visualization of the data, and more focus on making relationships and social graph data visible to people," she said.

LinkedIn, which was launched in 2003, is now expanding its user base at a rate of about two new members per second, Weiner said.

A free LinkedIn account lets members create profiles detailing their professional experience with a resume, biography and lists of skills, build a network of contacts, post comments and links, join groups, check out job postings and view news relevant to them.

Paid accounts give subscribers more features and capabilities, primarily in the area of job hunting. LinkedIn also offers paid accounts tailored for professional recruiters and for sales executives.

In the second quarter ended June 30, 2012, LinkedIn increased its revenue year over year by almost 90 percent to US$228.2 million, while net income fell 38 percent to $2.8 million. The company's shares closed at $111.20, up $0.35, or 0.32 percent, on Tuesday.