Yammer delivers private enterprise social networks to more than 200,000 organizations around the planet. People use it to collaborate securely across departments, geographies, and business applications. Microsoft purchased Yammer in 2012, and they wasted little time integrating it nicely with Microsoft Dynamics CRM.
Yammer integration enables Microsoft Dynamics CRM Online users to work together on sales and customer service records, using tools familiar to anyone who has used Facebook or the like. Which is to say, almost everyone. With Yammer, it is easy to stay up to date, because when someone creates or updates a record, the system automatically alerts you. You can ask questions, offer congratulations, and compare notes with others all in one place.
Yammer’s improvements were put in place on April 6th. If you are using an on-premises deployment of Microsoft Dynamics CRM, you must apply the latest updates or you will be unable to authenticate to Yammer, and the integration will no longer function. You can get the fix here.