We've been using it at our company since sometime around September with anywhere from 80-100 employees. Despite my efforts to get sales staff engaged in the product, they haven't picked it up because it isn't intuitive enough nor does it work similarly enough to Facebook (despite the visual rip) for them to be comfortable with it. I've had continued issues with the UX (enter posts instead of creating a line break, can't edit posts or replies, no way to organize posts by chronological order only instead of whichever post has the latest response, showing when private groups are created on the public wall, the way it deals with files/attachments, users not understanding how to stop receiving the sludge of email notifications it sends by default -- not to mention how it doesn't strip email signatures when you reply that way -- and lots of other things) on top of some gnarly early-2000s-esque UI. The product just looks and feels broken and I've been interested in seeing how larger organizations use it because (and I think I've posted this sentiment on HN before) there's got to be tools out there that are better put-together and user-friendly (Jive, et al?). As such, our staff still relies on email, document servers and our internal CRM.

Yes, a number of people at my company (with about 1000 people in it) tried to spread usage of it, but it only stuck with about < dozen people. Communicating through status messages doesn't really seem to give enough detail to anyone who needs to know.

Yep, we tried it and switched away from it because it simply didn't work; some messages failed to get through and it didn't seem to click with the team at all. I can't fathom what about it could be worth over a billion dollars.

We used it when I worked for TechCrunch (way back when). It's perfect for that setting: lots of writers, coordinating coverage, sharing interesting bits of information that you're not exactly sure who will find interesting. Etc.

It's not a good tool when it gets bastardized into a product management/planning/feature request tool. As a developer for them I was keenly aware of this flaw.

I've tried it in other contexts since leaving and it hasn't been a fit. Prefer HipChat/Trello.

I've always loved the concept but found the products so crappy (visually and UX) that I can't keep in the routine of using them.

Used it in last company, a good excuse to fool employees to stay away from Facebook yet use something similar at workplace.

A company I used to work for used it. I found the client to be really horrendous. It was written in some sort of god-awful Adobe Air thing that used 100% CPU constantly while it ran. Just awful, I can't comprehend why anyone would use a terrible bloated architecture like Air to create what should be a simple lightweight chat system. And the chat program itself had no advantages over any other chat system.

Maybe I just didn't "get it".