The document discusses the business value of adopting internal APIs within an enterprise. It argues that establishing internal APIs is an important first step before extending APIs externally, as it helps remove silos, enable an internal developer community, and extend the reach of applications within the organization. The document then covers various API adoption patterns, reference architectures for APIs including a unified API gateway and API gateway with ESB. It emphasizes that a unified API gateway can be a good starting point for many organizations.