If there is one theme that is common to just about every marketing book over the last few years, it would probably have to be adaptability. Businesses are advised to adapt to the growing complexity of our world with its technology, global competition, social media, and Millennials. Many of these books offer advice on how to deal with aspects of this complexity. You might find one book on how to market to Millennials. Another book deals with how to address your reputation online in a world where one misstep can be broadcast around the world.