Miller says he believes that the acquisition will primarily be used to bring social networking to SharePoint and Microsoft's Dynamics CRM, but other analysts see Yammer being linked to the whole gamut of Microsoft business products.

"They will integrate Yammer with absolutely all their cloud offerings, and they will also social-enable their on-premise software with web-based components," says . "What you have to remember is that Yammer is bringing on customers at a very fast rate, and every one of those customers is a potential Microsoft customer."

He also suggests another intriguing possibility: Bearing in mind that Microsoft can now draw on Yammer's expertise with the freemium cloud software model, it is possible that Microsoft may turn its entire Office365 service into a freemium offering which includes Yammer.

One of the first questions that many people asked when Microsoft announced the deal was whether the company would take Yammer and turn it in to an on-premise offering as well as offering a cloud-based service, in the same way that SharePoint is available to run on-premise or from the cloud. Microsoft indicated that this is unlikely in the near term, but has been far from definitive. "I don't think in a fully on-premises world we can imagine moving the cloud capabilities into the on premises" is how Microsoft's Delbene put it.

But given that Yammer's success has largely been based on the fact that as a cloud service it is available instantly to anyone and responsive to customers' needs of, it is hard to see how Microsoft could move to a cloud and on-premise hybrid model for Yammer without those benefits disappearing.