Marketing and advertising mediums have dramatically shifted over the past 10 years. The advertising agency of the past is now becoming a digital marketing agency. But just what marketing activities would fall under the digital marketing umbrella, and how can small to medium-sized business owners best utilize them? In this article - What Is Digital Marketing? A Guide to Marketing in Today's Digital World - digital marketing as it stands today is defined, and recommendations on how the small to medium-sized business owner can take full advantage of digital marketing media.