Tyco International case study - replacing your intranet with Yammer
Unlike most of the Yammer case studies I've seen, Tyco International set out with the deliberate objective of replacing their traditional static intranet with Yammer, in order to create a social intranet.
This video provides an introduction to the Tyco case study:
There is further detail in this presentation:
What might not be obvious from this deck, if you look closely at slide 11 you will notice that their time line included a content audit and content migration. This might sound surprising in a Yammer rollout, but clearly Tyco were trying to deal with a number of constraints (i.e. multiple intranets, no ability to devolve content ownership, network latency and site performance) that led them to Yammer as their global intranet solution that addressed both content and employee engagement.
In fact, it has been so successful that many of business units at Tyco have migrated from SharePoint to Yammer! According to Roland Hulme, a lot of business units had created workgroups in SharePoint but migrated to Yammer because it was cheaper (free in Yammer versus paid licenses for SharePoint).
To be quite honest, I'm not clear why they couldn't have just adopted any other hosted intranet solution to overcome some of their technical challenges. But despite the opinion of many being that tools like Yammer can't replace a traditional WCMS-based intranet (e.g. SharePoint), this is exactly what they have gone and done.