Question asked in the O365 Network: “Is there something that Yammer offers that really makes it more appropriate for discussion than Office 365 Groups, or is there a fair amount of overlap?”
The real answer to this actually reframes this in another question: How do you get the knowledge you need to do what you need to do?
When you think of how we tend to form our own phone, IM, email, or any-kind-of-Group circles of “go-to” people, for anything from direct knowledge to “this person will at least direct me to someone who knows,” this exclusive approach can both take time and waste time, even if you get the answer in the end.
Even more importantly, you may never know how much more awesome your idea or project could have been had you only looked outside your usual groups of go-tos.

Whoa! Talk to the paw there
While Yammer is not supposed to be the solution to every single scenario, it is a very viable solution to widening your circle, uncovering skills, and discovering influencers.
And in the process, it can help stitch your company together more firmly because now you’ve got this great big transparent knowledge base that becomes a go-to instead of a “Yam what?”
It does take nurturing and championship, but when you see people start organically thinking, “You should put that on Yammer” as part of their project or idea or decision, well, those are some pretty awesome moments.
Remember, you never know entirely who knows something or who can help. With Yammer, you can start to find out.