Microsoft didn't give specifics as to how it might integrate Yammer's technology into its products. It said Yammer will continue to develop its software, maintaining "its commitment to simplicity, innovation and cross-platform experiences." Microsoft will also work to accelerate Yammer's adoption in conjunction with complementary Microsoft products like SharePoint, Office 365, Dynamics and Skype.
"The key question is, how do we bring productivity, communications and collaboration from Microsoft into the Yammer world, and how do we surface people's professional social-networking relationships inside of what people do every day in Microsoft Office and other business applications, and we think there's just a tremendous, tremendous opportunity in doing both of those things," Ballmer said.
Microsoft seems to be approaching the acquisition with the right attitude of learning from Yammer's success and not interfering with its team and its development process, Cannell said. It's key for Yammer to be able to continue innovating in this space, he said.
Rob Koplowitz, a Forrester Research analyst, said Microsoft is choosing the best option for integrating Yammer into its business: Yammer is retaining a lot of independence, it will be part of the Office division and its cloud-based model will be supported.
"It's about as good a news as could have been hoped for in terms of how the deal could have been structured," Koplowitz said. "It's an acquisition, and those can always be a bit treacherous, but Microsoft is setting itself up for success."
Over time, Microsoft is likely to deepen the integration of Yammer into products like SharePoint, Office 365, Outlook and Lync, analysts said. That would continue a strategy Yammer has been pursuing for more than a year. It rolled out its first integration with SharePoint in 2010 and later enhanced it. In April this year, Yammer acquired U.K. company oneDrum, whose software lets users collaborate on Word, Excel and PowerPoint documents in real time.
However, Microsoft must also make sure Yammer continues to work well with products from other vendors, such as Salesforce.com and SAP, which it integrates with via custom connectors and using Yammer's open API (application programming interface), Koplowitz said.
"Yammer already has an aggressive integration strategy with Microsoft products, and they'll continue on with that. The concern is whether Yammer will become too focused on Microsoft integrations to the exclusion of other vendors," Koplowitz said. "Yammer has been playing Switzerland. It shouldn't now favor Microsoft and reduce the potential of a broader integration portfolio."
No timetable was given for the closing of the deal, which is subject to regulatory and other approvals. News of a possible deal between Microsoft and Yammer emerged on June 14, when, citing anonymous sources, Bloomberg reported that Microsoft was in advanced talks to acquire Yammer for about $1 billion.
Yammer's software is used by more than 5 million corporate users and in more than 85 percent of the Fortune 500 companies. It offers a basic free version of its software and three fee-based tiers. Yammer, which has raised $142 million in funding, has about 300 employees.
About 200,000 businesses use Yammer in more than 150 countries, DelBene said. One such customer is Deloitte, which rolled out Yammer to 190,000 employees, he said.
Yammer adds about 250,000 corporate end users every month, according to Sacks. Its other customers include Tyco, Ford and Nationwide Insurance.
The deal triggered reactions from several Yammer competitors who emailed statements to the press.