Microsoft acquires Yammer.com

Almost four years after it was launched, the social networking site Yammer.com was acquired by the multinational corporation Microsoft.

Yammer is a social network for the businesses. It is categorized as an enterprise social network. It's tag line says, "Collaborate securely across departments, geographies, content and business applications."

Because of its popularity and the ease of use, the social enterprise social network has more than two-hundred thousand companies using it.