Adweek: BuzzFeed made a name for itself with a cross-platform distribution model that relies heavily on publishing to social platforms. Now, it’s looking to leverage that reach. BuzzFeed has unveiled a beta test of an ad format dubbed Swarm. It allows advertisers to run campaigns simultaneously across all of his company’s web and mobile properties and six of its social platforms: Snapchat Discover, Vine, YouTube, Facebook, Instagram and Tumblr.