Owned by Microsoft
Collects and sells data
No private setting
Unable to be monitored
Allows direct messaging between employees
What Yammer says, "The Yammer mobile app helps you stay connected from anywhere - driving employee engagement and participation across the entire company as nothing else can. Yammer helps you connect with leaders and peers, share and discover knowledge and engage in org-wide communities that matter to you."
What SGS says, "Only for use within a company or business. Not recommended for anyone under 18. Important to stay on brand all the time because you are posting for your fellow employees."