With the rise of social networks, professing one’s love for a particular brand is as simple as clicking “Like” on a Facebook page. But, for Facebook, that activity can be somewhat siloed: You’re either preaching to the choir on a fan page or sharing that love with your circle of friends via status updates. While that may not irk the average “Twilight” fan, it’s a potential thorn in the paw of social media marketers who want their campaigns to go viral. Enter CrowdFanatic , the recently launched app that lets fans interact on Facebook by pitting opposing groups against one another. Thus, Google Android fans can challenge Apple zealots in an “arena,” a page where participants can exchange comments back and forth, making the case for their particular beloved product. From there, anyone can share a link to the discussion to attract others. In other words, the app essentially gives fanboys of different stripes a battleground to duke it out in. In a time where viral marketing can make or break a given product (the Pebble smart watch , for example), the idea is an interesting one for brands looking for a wider reach. Get enough users to rally behind your cause — be it a movie, a political candidate or a laundry detergent — and the court of public opinion could turn more customers and supporters your way. While individual fans can start their own “arenas,” the most obvious use case is for social media marketing campaigns. The app is currently free to all Facebook users, but founder Yaron Bazaz and his team are currently working on a plug-in for Facebook brand pages, wherein companies could connect CrowdFanatic to their page for a licensing fee, as well as a cut of the revenue share from an online donation system