This fall, Yammer released the latest version of its product, which brings it ever closer to a combination of Twitter and Facebook for business.  Yammer has expanded to include applications like links, polls, chats and events, and companies that are using this product say it fosters better communication and growth of relationships between co-workers.

Unlike Twitter, which is used for broadcasting messages to the public, Yammer is used for private communication within organizations or between organizational members and pre-designated groups, making it an example of enterprise social software.

Access to a Yammer network is determined by a user’s internet domain, so only those with appropriate email addresses may join their respective networks.

According to TechCrunch, the service is being used by more than one million users and 80,000 companies worldwide (that includes 80% of the Fortune 500). And Yammer is doubling revenue every quarter. A quote on the Yammer website from one of their customers says, “It’s helped drive innovation and build community”, “we’re finding new value in the tool every day.”

The price point for Yammer is great for small businesses – $5 per month per user, with discounts available to non-profit organizations.   It is definitely something to investigate if you’re interested in enterprise social networking.