Salesforce.com [NYSE: CRM], the enterprise cloud computing  company,has entered into a definitive agreement to acquire Buddy Media, the world’s leading social media marketing platform, for approximately $689 million payable in cash and salesforce.com equity.

The transaction is expected to be completed during salesforce.com’s fiscal third quarter ending October 31, 2012, and is subject to customary closing conditions.

“Social media has caused the biggest transformation in marketing since the Mad Men era, causing CMOs to completely re-think their strategies,” said Marcel LeBrun, SVP of Salesforce Radian6.

“By bringing together market leaders Radian6 and Buddy Media, we are doubling down on the Salesforce Marketing Cloud to provide CMOs with the ability to manage the entire social marketing lifecycle.”

Speakers from Buddy Media have participated in several of TechMedia’s events, including the Digital Summit held in May in Atlanta, and the Internet Summit in Raleigh last year, among others. The next TechMedia event is Digital East in Tysons Corner, VA, and the Internet Summit returns to Raleigh in November.

Here’s an unusual video “We Got Bought,” from Buddy Media CEO Michael Lazerow that is getting some online attention (he doesn’t speak a word):