In another game of pac-man, Microsoft has bought Yammer for $1 billion.

For those of you who have no idea who/what Yammer is. Yammer is a social network for working people. A business version of Facebook, all the way down to the looks and feel. Yammer will not allow you to sign up from an email account which is not related to the domain of the company you’re listing yourself as an employee for.

Yammer has boasted integration with Microsoft’s SharePoint since 2010, so the two already have a link. In February 2012, Yammer was valued at being worth $500,000,000. Microsoft had just bought Skype an year ago for $8.5 Billion, and this move is being taken as Microsoft’s attempt to launch themselves in the world of corporate social networking.