The survival of application systems in the digital world is like the survival of animals in the wild nature: a ruthless evolution, were only the fittest will prevail and the others will succumb to the uninstall binaries or get buried in the depths of the recycle bin.
This book will help you to create faster and more reliable systems, so that your code will last for all eternity (or at least to the next release cycle). Being able to provide great working applications that make your customers happy, you will be able to generate higher income, either as an employee or as a company.
By not knowing the contents of this book, you can cause yourself endless and reoccurring discussions and involvement in task forces about slow systems. You might lose a customer or will not get promoted and miss out on some extra cash. Get this book and read it to get a lot of hints on how to avoid such situations in the first place.