Life in the SharePoint partner ecosystem is a mixed bag.

On the one hand, Microsoft cleverly slips SharePoint into enterprises via MS Office-addicted knowledge workers. It spreads faster than orders for tomato juice on a trans-Atlantic flight, and by the time the CIO and the CFO wake up, the hook has been set.  According to Microsoft, the result of this addiction is more than 125 million licenses, somewhere around $2 billion in revenue, and usage by 80% of the Fortune 500.

Feeding the SharePoint craving

Consuming all of that SharePoint actually creates even more appetite among users. Thanks to the significant gaps in some SharePoint workloads, coupled with Microsoft’s leisurely release cycles, their partners can make many billions more selling extensions, enhancements, and replacements for SharePoint feature sets.

But while they’re bringing in the sheaves, SharePoint partners have to keep looking over their shoulders. Will the new release plug the gap addressed by my third-party solution? Maybe, but those 3+ year development cycles mean that it is virtually impossible for SharePoint to offer functionality that matches the products from smaller, faster, and more agile partners. (Case in point: enterprise social. The 2010 version did a great job addressing SharePoint 2007’s yawning abyss around social functionality. But by the time it was released, 2010 was already no match for the social solutions from the likes of Newsgator, Jive, and Confluence.)

Can’t build it? Then buy it.

So the right way for Microsoft to get cutting edge, best-of-breed functionality is to buy it, and that’s the main source of anxiety for the partners (that is, the ones that aren’t bought). Here again, Microsoft has demonstrated, shall we say, remarkable constraint in the face of obvious opportunities. (Will they finally pick up one of the leading .NET WCM solutions?)

The purchase of Skype last year for $8.5 billion was a bold move that has yet to prove itself. Today’s rumored acquisition of Yammer is easier to understand and has more potential to pay off.  Box, Huddle, Jive, and Yammer have proven an appetite exists among knowledge workers for collaboration support that goes far beyond sticking files in shared folders. Buying Yammer gives Microsoft immediate access to the functionality (since it’s cloud-based) and a proven integration with SharePoint at a reasonable price. (According to my rough calculations of comparative free cash flow and 12 month trailing earnings, Microsoft paying around $1 billion to acquire Yammer is equivalent to me paying $7.95 to acquire lunch.)

What are the key takeaways?

• Microsoft finally understands that, sometimes, cash can beat code. Over at ZDNet, Larry Dignan wonders “Couldn’t one of Microsoft’s . . . skunkworks teams build something similar [to Yammer]?” Maybe they could, but evidently they didn’t. I heard mostly unimpressed yawns from people who’ve previewed the next release of SharePoint.  Aquiring Yammer solves Microsoft’s best-of-breed problem on social in an instant.

• Enterprise social curmudgeons need to find a new bridge to sit under. Just in time for next week’s E2.0 conference in Boston, Microsoft’s move validates the impact and importance of social in the enterprise.  How so? Maybe it’s just a really silly decision. True, but what motivates the decision? Microsoft cares about social because IBM and Oracle do, and are investing heavily in it. So the real validation is IBM’s impressive success with the social business theme.

• Digital disruption wins. Again. Yammer is less than four years old, and typifies the cloud-based, agile, and lean digital disruptors that are challenging the traditional, on-premise, big ticket, CAPEX licensing and sales model of the established platform players typified by Microsoft. It remains to be seen whether Microsoft recognizes that you can’t beat digital disruption, you can only be it. The big mistake would be to swallow Yammer up into the SharePoint beast rather than letting them continue to offer the responsiveness and rapid development customers appreciate.

• Crocodile tears for NewsGator. No, make that real tears. Uncontrolled, jilted at the altar sobbing.  NewsGator was supposed to be SharePoint’s social squeeze. In fact, the two are such intimate friends-with-benefits that NewsGator’s Social Sites don’t even run outside of SharePoint. Yes, NewsGator will put on a happy face, and yes, some customers will still prefer the deeper integration with SharePoint. But right now, NewsGator is Kiefer Sutherland and Yammer is Jason Patric.

(Moreover, the fact that Yammer isn’t directly tied to SharePoint allows Microsoft to deploy it against the other enemies – Google and Apple, plus   whichever upstarts they acquire. The value of Box and Huddle just went up.)

I know, this isn’t all about SharePoint. Yammer will (or should) have an impact on other Microsoft applications, such as CRM, and Office in general. But in any case, Microsoft wants to blur the lines between Office and SharePoint, and this move is primarily about blowing some nitro into the SharePoint 2013 launch. Plan to see a lot of Yammer CEO David Sacks at the November SharePoint event in Las Vegas.