Identify the right use cases

When you launch Yammer in your organization, it's critical that you identify the best use cases to make your launch successful. Here are a few examples to get you started:

Build community around common interests to help connect users so they can share expertise and resources.
Cultivate executive engagement so that your organization feels connected to the senior leadership team.
Engage your front line to give feedback from customers and escalate issues no matter where people are located.
Drive ideation and innovation by sharing ideas openly, getting crowdsourced feedback, and using @mentions to get experts involved in the conversation.

Source: Microsoft