You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract You Choose: The Funniest Viral Ad Campaign of the Year Six Entries From Liquid Plumr, Pepsi Max, Old Spice, Le Trefle, AT&T, Smartwater and Melbourne Transit By Michael Learmonth, Published on March 19, 2013 22 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.