Despite the clamor around Facebook (Nasdaq: FB), the No. 1 social networking site, the real king of the social networking sector is International Business Machines Corp. (NYSE: IBM), a new survey by IDC found.

Coming in second: Jive Software (Nasdaq: JIVE), of Palo Alto, Calif., with huge year-over-year gains by private Yammer, of San Francisco, which investment bankers speculate is about to be acquired by Microsoft (Nasdaq: MSFT), the world's biggest software company, for about $1 billion.

The reason is that these social networking companies specialize in the enterprise, or networks of users throughout companies, universities or government agencies whereas Facebook is very consumer-centric.

We are engaging people in mission-critical applications, said IBM VP for Social Software Jeff Schick. Our capabilities are focused on business optimization.

Besides involving nearly all of the Armonk, N.Y., computer company's 433,000 employees, IBM's social media software has been deployed by the United Nations, banks like Canada's Toronto-Dominion (NYSE: TD); retailers like Lowe's Companies (NYSE: LOW), the No. 2 U.S. home improvement chain and appliances giant Electrolux AB (Pink: ELUXY).

Schick said IBM uses many of the same internal applications for customers in a secure environment so that they can collaborate in groups for mutual benefit.

For example, he said after TD Bank acquired several U.S. banks that were open on Sundays, the new U.S. employees used social media to explain to their Canadian counterparts why the practice led to new customers and business and then helped them develop the same service to Canada.

The enterprise social networking market rose about 40 percent between 2010 and 2011 alone, IDC concluded. By 2016, the market value could reach $4.5 billion, for about 43 percent annual growth.

IDC also found the top six social networks currently claim more than 2 billion global users. Twitter dispatches about 340 million daily tweets. Facebook users share about 30 billion content units monthly.

Meanwhile, IBM's Schick said the company is planning for major growth in social networking, which will also be secure. By 2014, we need to think about which business processes will change, he said, citing as examples the method insurance companies handle price changes for claims or banks their mortgage applications.

In Monday trading, IBM shares fell 81 cents to close at $198.29, Jive Software shares rose 91 cents to $20.63 and Facebook shares rose $1.48 to $31.49.