Yammer launched live on stage at the TechCrunch50 conference, on September 2008.
"David Sacks, the founder of genealogy site Geni, just launched a new company called Yammer on stage at TechCrunch50. Yammer is an enterprise version of Twitter. If Twitter asks: “What Are You Doing?”, Yammer asks: “What Are You Working On?” Engineers at Geni created Yammer internally for the company’s own purposes, but Sacks liked it so much he decided to spin it off as its own company. He explains:
The purpose is to allow co-workers to share status updates. You post updates on what you are working on. You can post news, links, ask questions, and get answers for people in your company.
You can see most the most prolific people and the most followed people. It is a good way to discover who is the most influential in your company."
Yammer is a free service, but companies can claim their networks to get administrative rights and security features for one dollar per user per month.