Books for digital marketing?

First I’d like to start out with a joke:

Next I’d like to ask are there any good books on how to break into digital marketing?

Digital marketing is a very broad term, with lots of nuances. Which aspect of digital marketing are you looking onto?


Maybe an overview of all the aspects of digital marketing in general. I would say I am most interested in SEM/SEO as I believe that to be the most powerful, but not sure. Thanks.