"Maybe only a few [staff] will use it,
A few staff, yeah. Marketing and Sales. No one else. Of course, by definition, that makes it a huge success because "everyone"[*] loves it and uses it all the time.
We've had a few various "social media-like" things at our workplace over the years. In almost every case there were specific "channels" set up and only the sales and marketing ones saw much use. I remember the first one they tried and those same marketing and sales people seemed to think it was their personal Facebook account, posting the same sort of drivel they put on there. It took a couple of months for someone senior to finally stamp on that and point out it was meant for business use. At which point it turned into a wasteland :-)
On the other hand, now we have a better system where individual teams have their own channels, created as needed, and it does get used properly and relatively frequently. This is because anyone from team leader and up can create channels rather than top-down defined channels made be people who see the "big picture" but have no idea what individual staff need, want or do. The company wide channels and/or anything at division level are barely used.
[*] ie, of those polled by Marketing and Sales, ie only those who actually thought it was "exciting" stuff and joined in.