LinkedIn hit the half billion member mark, continuing its pace of adding 50 million members every nine months.  LinkedIn also supports ten million job listings and over nine million company profiles.  Members continue to post 100,000 articles per week.  However, the active monthly user rate remains around 25%.

In comparison, Facebook has 1.8 billion members and Twitter has 328 million.  The top five countries are the United States (138 million), India (42 million), China (31 million), Brazil (29 million), and United Kingdom (23 million).

LinkedIn published connection data by country and region for the first time with the top five most connected countries (i.e. average member connections) listed as the UAE, Netherlands, Singapore, UK, and Denmark.  UAE profiles average 211 connections.  By metro area, London leads in average connections with 307 per member followed by Amsterdam, San Francisco, Jakarta, and Milan.  Staffing and recruiting is LinkedIn’s most connected industry (unsurprisingly as the firm’s largest revenue source is their Talent Solutions products), and human relations its most connected job function.

LinkedIn connectivity rates by job function and level indicate a strong focus on staffing, consulting, and PE/VC roles.

The top five industries are all highly networked occupations including staffing and recruiting, VC/PE, human resources, management consulting, and online media.  With respect to job functions, product management was the number two most connected occupation after human resources.  It was surprising to see that sales reps did not even make the top five (outside of Business Development which is a senior level mix of partnership, licensing, and relationship management), but product managers had very high connectivity.  Of course, the sales function would span both junior and senior sales reps along with business and consumer sales, while product management consists of more mid and upper-level management.

“The impact of half a billion professionals connecting and communicating is very real, and very accessible to anyone who wants to take part today,” said Aatif Awan, LinkedIn’s VP of growth and international products.  “We’re excited to think about the potential of what a highly connected global community of professionals can do, and the value that is created for every member of the global workforce.”

LinkedIn, which is operated as an autonomous division within Microsoft, has over 10,000 employees.