Social networking is one of the big three themes of 2011, along with Cloud Computing and Mobility.

Salesforce.com has been pushing its Chatter social networking platform for the corporate class with the new public service, Chatter.com, promoted with two ads during the Super Bowl halftime show.

Today, Constant Contact made a move to keep pace with the social networking expectations of its customers by acquiring Bantam Live, a contact management and social CRM provider for $15 million. This acquisition follows Constant Contact’s purchase of NutshellMail last May which enabled the email marketing company to link its messages to Twitter and Facebook.

The Bantam Live acquisitoin goes beyond simply giving Constant Contact subscribers a Facebook-like user interface and experience. It also includes contact/CRM, task management, calendaring, deal tracking, and project management, among other capabilities.

By adding these functionalities onto its email marketing platform, Constant Contact is pushing to dramatically expand its role within its customer accounts. Rather than being a tool which users only open when they are conducting email campaigns, a broader set of potential users now have multiple reasons to utilize it to coordinate a wider array of everyday activities.

In fact, if social networking tools like Facebook and Twitter continue to outpace traditional email as the primary communications and collaboration platform for a new generation of businesspeople, then Constant Contact could become the MS Outlook of the future for a broad, cross-section of small- and mid-size businesses (SMBs) which already depend on its email marketing capabilities.

Some might suggest that the modest price paid for Bantam Live diminishes its strategic importance. All you have to do to dispel that idea is to look at the major impact Salesforce.com’s unheralded acquisition of GroupSwim at the end of 2009 that became a cornerstone of Chatter.

Many in the SaaS/Cloud world have been speculating about when Salesforce.com will acquire a marketing automation vendor to round out its ‘Sales Cloud’. Now, Constant Contact is suggesting that its marketing automation platform could be the centerpiece of a broader set of day-to-day business functions.

Disclosure: I’m a Constant Contact user and Salesforce.com is a THINKstrategies client.