Microsoft has just made its biggest acquisition by buying LinkedIn. Beyond the impressive bill left by the purchase (I’ll let you calculate the cost/user ratio), what many will analyze remains the reason for the purchase—the why?

Satya Nadella, CEO of Microsoft, clearly announces his plan and the intentions of the new couple:

Together we seek to empower every person and organization on the planet

The ambitions are clear, the action plan less so, but what lies behind this marriage?

As I had already explained, networks in the information age must be both centralized AND decentralized, capable of managing the person AND the group, or even better, hosting all the stakeholders of our organizations:

The Social Graph must absolutely open up to the Web and not remain confined to the company’s walls alone

LinkedIn being undoubtedly the most comprehensive B2B database in the world, couple its graph with the capabilities of the Office 365 platform and you have a more than interesting preview of the future capabilities the couple will be able to offer us.

This acquisition may even signal the imminent approaching death of enterprise social networks, or at least the beginnings of a redesign of their way of doing business. The Microsoft/LinkedIn couple lays the groundwork for a convergent platform that addresses market failures and could quickly settle the score with competitors too self-centered on themselves, where the stakes are mainly played at the opposite of their initial concepts. They simply don’t play on the same field…

While everything happens outside the company, traditional enterprise social networks lock us in. The traditional social network, promised to become the unique work tool, closes in on itself and risks disappearing in favor of digital hubs, directly integrated into the heart of the main players of the Social Web.

The Microsoft teams are doing better than this little prediction. They are simply acquiring one of the main hubs of the global social graph. In return, this merger will create a new web giant alongside Google and Facebook, a hub that opens up the enterprise to the possibilities of a Web that it still only sees as an option.

Finally, Microsoft, which had missed the social turn, fills the gap of a history strongly oriented toward “the enterprise” that it simply hadn’t been able to negotiate!