Yammer is a freemium enterprise social networking service used for private communication within organizations. Access to a Yammer network is determined by a user's Internet domain so that only individuals with approved email addresses may join their respective networks.
Initially, the Yammer platform was developed as an internal communication system for the Geni.com genealogy website, and was launched as an independent product in 2008. Microsoft acquired Yammer in 2012 for US$1.2 billion. Currently Yammer is included in all enterprise plans of Microsoft 365.
The company Yammer began work on September 8, 2008 at the TechCrunch50 conference. The basis of the service lay the concept of Yammer, which in the course of work on the startup was developed by the co-founder of the company David Sachs, until 2002 held a senior position in PayPal. In addition to the functionality for communication, Yammer provides third-party developers the ability to create and sell their collaborative applications directly to platform users.
Saks, CEO of Yammer, said that until April 2010, Yammer's revenues doubled every quarter, but did not disclose the company's earnings for 2009, noting only that they were expressed in a seven-digit number. Sachs also said that at that time, Yammer used 70 percent of Fortune 500 companies.
In September 2010, more than three million users and 80,000 companies from around the world used the service, including 80 percent of Fortune 500 companies. At the same time, Yammer 2.0 was launched, and the new version was called Business Facebook.
June 25, 2012 Microsoft bought Yammer for 1.2 billion dollars, paying the deal in cash. After the acquisition, Microsoft announced that Yammer will be part of the Microsoft Office, but will remain in Sachs' jurisdiction.