We have Yammer. We are required, by company policy, to use it (various senior types get junkets from MS, we have to follow the latest MS fashions; they even think Win8 will trump Apple).
The only ones who do use Yammer are the sales-and-marketing drones who want to suck off each others' egos. The engineers do their best to ignore Yammer and spam-hole the deluge of utter drivel. I do not give a shit if Jack just had an exciting phone convo with the PA for someone who might be a potential lead maybe. Nor the ten replies of mutual masturbation.
Furthermore, when used for "confidential" business "war room" stragey debates, what kind of fuck-nut wants to put all that (unencrypted) on a server beyond company control? In fact, who wants to put next year's plans in the hands of a known monopoly abuser who is also a potential comprtitor? Or in the control of a foreign power?
Screw Yammer. Screw 99% of this social media bullshit. Not everyone needs to know everything about everyone else all the time. It just becomes noise.
And engingeering certainly does not give two damns about the free toy MS gave you (which every sane person hates) but which we now have to supprt because marketing have the MS cock rammed in their mouth so hard it has impregnated what passes for a brain in that department.