Traditional marketing puts content in front of a passive, potentially uninterested audience. Search engine optimization (SEO) helps you target a different kind of crowd, the millions of people actively searching—typing on their phones and laptops or speaking to their Amazon Echo or Siri—for exactly what you're selling. LinkedIn influencer Danny Sullivan has been in on SEO since its early days, and educates businesses about the power of SEO as the chief content officer at Third Door Media and cofounder of Search Engine Land.