Microsoft (Nasdaq: MSFT) wants to yam it up.

Even though Microsoft made an early $240 million investment in Facebook (Nasdaq: FB) back in 2007, the software giant has still always had social intentions. Since then, the two have taken their relationship to the next level in various ways, from integrating Bing into Facebook's search bar to selling some old AOL patents to the social networker for $550 million.

Rumors are now surfacing that Microsoft is in the process of acquiring Yammer, an enterprise-centric social network start-up. The service facilitates collaboration and information sharing within companies and is different from the dominant professional social network LinkedIn (Nasdaq: LNKD). Yammer bears an uncanny resemblance to another social network we all know and love, except with a different color theme.

Source: Yammer.

Yammer focuses on creating social networks within companies, but it helps you build external networks as well. It boasts 200,000 enterprise customers, including 85% of the Fortune 500. Its customer base is fairly diverse, including names like eBay, Ford, and Intuit, among others.

Acquiring the start-up would kick up Microsoft's competition with salesforce.com (NYSE: CRM), which has been putting a big emphasis on social enterprise of late, recently acquiring Buddy Media. Salesforce's Chatter offering is a replica of Yammer's value proposition.

Source: salesforce.com.

Back in February, Yammer had raised about $85 million in funding at a valuation of $500 million, and Bloomberg is separately corroborating the speculation and even adding a potential price tag of $1 billion to the deal, which could be inked as early as tomorrow.

Social is the next big thing in the enterprise for investors, and Microsoft is buying its ticket in. For a pure play on the social-media craze, this is the stock you should be buying. Its future is much more promising than other social plays, including Facebook, thanks to its healthy monetization model. Grab this free report for more info.