Microsoft confirms earlier rumours by confirming the purchase of enterprise social networking services developer Yammer for $1.2 billion in cash.
Yammer now becomes part of the Microsoft Office Division, even if employees will continue reporting to Yammer CEO David Sacks.
The purchase is the 2nd biggest for Microsoft since the $8.5bn acquisition of Skype back in May 2011.
Microsoft says it will "accelerate Yammer's adoption alongside complementary offerings from Microsoft SharePoint, Office 365, Microsoft Dynamics and Skype," hinting at further SharePoint-Yammer integration.
It also makes sense for Microsoft to integrate Yammer with Office 365 cloud-based application suite.
Founded in 2008, Yammer describes itself as "the enterprise social network" and offers a collaboration and data sharing environment that is more Facebook than Microsoft Office. It boasts 5 million corporate users from 200000 companies, including the likes of Ford and EBay.