[mbesto]

What has changed about that market that makes this more appealing to businesses than Yammer? OR what about the product makes it more compelling than Yammer?

[draaglom]

"More compelling than Yammer" does not strike me as a high bar.

[Spooky23]

From the description, it sounds like Yammer before they grafted SharePoint to it.

I suppose that makes it better than Yammer by default. :)

[nickpsecurity]

Particularly, Facebook's history of unethial actions regarding private data. It should almost be criminal for IT shop to put confidential info on a Facebook service.