I don't know if you had an opportunity to see this session at Ignite, but if not I suggest you take a look now. Most of the data is provided in the first 15 minutes or so, but if even that is to long then think of this.
In our day to day work life we work with different groups and we engage with those different groups differently depending on how close we are, now when I say close I don't mean geographically, I mean the relationship with them. The idea is that you have two loops that your co-workers/vendors/customers fall into
Inner loop - These are people that you work with often and have created deep relationships like a manager or team member, you're going to use tools like SharePoint and Teams to interact with them on a daily basis.
Outer Loop - These are people that you are aware of but probably don't really work with normally like an Executive at your company, occasionally you might need to collaborate with them or they might need to collaborate with you. For these people we recommend broader social tools like Yammer.
And then you have tools like email and Excel which can cross both loops, the speaker goes thru some great ideas about how to analyze what tools are best for your enterprise and how to get your users to adopt them.