The Washington D.C.-based National Retail Federation, which is holding its annual loss prevention conference in New Orleans through Friday, highlighted companies that are taking a lead in effective online customer-engagement strategies. John Lazarchic, PETCO Animal Supplies Inc. vice president of e-commerce, and others weighed in on 2012 trends in e-commerce, which is focusing on building an online community of users through interactive content that has traditionally been the purvey of online media. Here are five retailers that are taking a lead in online community engagement.