Editor’s note: This is a guest post by Lawrence Coburn, the CEO of DoubleDutch, creators of Pride, a free, mobile only, collaboration app for business teams.  Try it here.

Our nascent industry’s fastest growing, best capitalized, and highest profile startup is apparently getting absorbed by Microsoft for over $1B.

While it took Yammer four years to go from zero to a billion in valuation (versus Instagram’s 1.5 years), it still represents extraordinary execution.

“Disciplined” is the best way to describe Yammer’s product vision. They bet early and hard on the consumerization of the enterprise, and did not deviate much, if at all, from the Twitter / Facebook blueprint. More recently, they methodically banged off integration after integration, increasing their addressable market with each hook.

Where Yammer innovated was on the distribution side.

They went all in on freemium before it was hip to do so, and used the time-tested “fear and control” pitch to CTOs to drive conversions. Yammer’s easy access to capital by virtue of its proven management team allowed them to keep their foot on the gas, despite allegedly deprioritizing revenue as a growth metric.

The synergies with Microsoft are obvious – with Sharepoint, Microsoft has been working on collaborative enterprise desktop software as long as anyone in the industry. $1.2B is simply the tax that Microsoft has to pay for a failure to take the social cues from consumer software fast enough. Yammer should help them immediately.

And for Yammer, Microsoft is the ultimate distribution channel, whether it be through Sharepoint, Microsoft Dynamics, Office 365, or even Windows.

So where does this leave the rest of the enterprise social software landscape?

Oh man, I think we are just getting started.

ALL of the incumbents are deeply flawed. SAP, Oracle, and even Salesforce, are reliant on systems that were architected for a different era, and have not yet shown a product fluency with social. And each is no doubt looking to opportunistically snap up social enterprise startups, lending plenty of incentives to those working on rethinking enterprise software.

But the elephant in the room is mobile.

Two years from now, I can’t imagine that employees will be collaborating on desktop first systems.

A look to the consumer world will show you just how disruptive the mobile rocketship is. Facebook, for all of its youth, engineering might, vision, and grasp of social, is struggling to convince Wall Street that it will thrive in a mobile first world. And if Facebook can’t grok mobile (at least from a monetization perspective), where does that leave the old school enterprise?

From where I’m sitting, enterprise remains the most exciting and unexplored market for technology in the world, especially at that sweet spot between mobile, social, and cloud.

If the reports of its acquisition are true, Yammer deserves huge credit for its relentless, disciplined, and methodical race to a $1B exit.

I’m even more excited about the services that come next.

Image credit: Lambda’s