Catalog-integrated ebook demand-driven acquisitions (DDA) has been one of the most significant changes to the acquisitions process of the past decade. DDA is disruptive because it represents a fundamental change to the nature library collection development. This chapter introduces the concept of DDA and outlines the structure of the book. This book is aimed at preparing librarians and library professionals to assess their existing DDA programs using examples from other libraries in the form of research discussions and case studies. This book will also be appropriate for readers that are interested in beginning DDA programs and want to ensure that they build programs with strong assessment strategies and clear goals.