Book excerpt: Digital marketing now represents 25% of the marketing spend in the UK and this is predicted to move to 50% or higher within the next three years. Understanding Digital Marketing looks at the world of digital marketing: how it got started, how it got to where it is today, and where the thought leaders in the industry believe it is headed in the future. This authoritative title demonstrates how to harness the power of digital media and use it to achieve the utmost success in business, now and in the future.Understanding Digital Marketing deals with every key topic in detail, including:search marketing,social media, Google, mobile marketing, affiliate marketing, e-mail marketing, customer engagement and digital marketing strategies. Essential reading for both practitioners and students alike, and including real-world examples of digital marketing successes and expert opinions, Understanding Digital Marketing provides you with tools to utilize the power of the internet to take your company wherever you want it to go.