Microsoft acquired Yammer in 2012 for about $1.2 billion.
Yammer was founded in 2008 by David Sacks as an enterprise social-networking service. It allowed employees to communicate through private, company-focused networks using familiar social-media features such as feeds, groups, and messaging. Microsoft announced the acquisition in June 2012 and completed it in July.
The purchase strengthened Microsoft’s business-software portfolio by adding a collaboration network aimed at organizations rather than the general public. Yammer remained a standalone service for several years, while Microsoft connected its capabilities with products such as SharePoint, Office 365, and later Microsoft Teams.
Yammer is easy to confuse with consumer social networks because its interface resembled services such as Facebook. Its defining feature was controlled workplace access: users generally joined networks associated with their organizations. Microsoft eventually retired the Yammer brand in favor of Viva Engage, announced as part of its broader employee-experience strategy in 2023.