Yammer Cofounder David Sacks Is Out At Microsoft

It's been two years since Microsoft acquired business social network site Yammer for $1.2 billion and the cofounder of the company, David Sachs, announced on Twitter on Thursday that he's leaving Microsoft.

Thank you to my current and former YamFamily for 6 great years and to Microsoft for the last two. I look forward to new adventures.

- David Sacks (@DavidSacks) July 24, 2014

Yammer had been running as a fairly independent unit, even as its tech was integrated into various Microsoft products like SharePoint and Office 365 (the cloud version of Microsoft Office).

But now Microsoft is moving Yammer into the Office 365 and Outlook development teams, which are headed by Microsoft Corporate Vice President Rajesh Jha, reports Mary Jo Foley.

Microsoft CEO Satya Nadella has been warning that he is reorganizing the company to streamline it. So it's perhaps not surprising that Yammer is being folded into a bigger team and Sacks would leave.

Yammer was part of former CEO Steve Ballmer's grand vision. Yammer was supposed to teach Microsoft about "viral adoption." Ballmer even coined a term "Yammerization," which Microsoft told us, "is about designing software for viral, voluntary adoption, but with enterprise-grade controls and reliability."

But a year after the acquisition, Microsoft changed its tune. Instead of creating more software for viral adoption, it viewed Yammer as "a freemium on-ramp to other Microsoft services," Yammer's other cofounder Adam Pisoni told us.

As for Sack's departure, Pisoni tweeted, "We were an unlikely pair, but that's also probably what made us special. Thanks again @DavidSacks for the wild ride."

Before Yammer, Sacks was PayPal's chief operating officer.

Microsoft sent Foley the following comment about Sack's departure:

Yammer is an integral part of Office 365 and it is being used by more than 500,000 organizations to transform how they work every day. Since we acquired Yammer in 2012 we have been working together to bring the integrated benefits of enterprise social to all our Office 365 customers. As we've seen the Yammer experience extending throughout Office - giving people new ways to collaborate and work together - it's now time to bring the Yammer organization together with our Outlook and Office 365 Shared teams as the next logical step in delivering an integrated set of social, collaboration, and communication experiences that enable companies to work like a network.

We thank David for his commitment to Yammer and Microsoft and wish him the best in his future endeavors.Yammer has grown tremendously since the acquisition in 2012, and is now an integral part of Office 365 and used by more than 500,000 organizations. As part of our long term plan, David has played an instrumental role over the past two years in building a strong leadership team to set a solid direction for Yammer as part of Microsoft Office 365 and our vision for enterprise social."