In this chapter we try to shed light on the main descriptive models of the Internet, what is meant by the Internet industry and how it is characterized, analyzing the main studies that have attempted to define, structure and measure the network economy, highlighting how, in fact, a framework is still missing.

The first chapter is therefore structured in two parts of analysis:

• In the first part, called the general models of the Internet, we try to define and classify the Internet phenomenon according to some general drivers, and in particular the economic, relational and technological exchange driver. Each of these three dimensions allows a first interpretation of the phenomenon, which serves to frame the relational dynamics that frame the Internet in a context in which we can identify: an economic value of exchange between different services (Internet as an economic system), a relational process that guides the relationships between individuals (Internet as a Complex Adaptive System or CAS Complex Adaptive System), a technological tool transversal to complementary sectors, products and services (General Purpose Technology, GPT) and finally those that are the social influences deriving from the adoption of specific technological systems (Large Technological System, LTS).
• In the second part we will analyze specific models that describe the Internet industry focusing on layered models, the first models that emerged to describe the industry (Model CREC 1998; Model Internet Intermediaries – OECD, 2010; Internet economy model – IDC, 2011; Internet Stack – BCG 2011), the flow models, which tried to define the industry by identifying the economic flows between the industrial sectors of the Internet (The Internet Money Flows – O’Donnell, 2002; The Internet Ecosystem – Hamilton, 2007), and the models that have tried to describe the industry using the value chain approach (Internet Value Chain – AT Kearney, 2010).

After the two parts of the analysis we will move on to the introduction of an analysis framework, developed in order to try to give a structured approach to the study of the Internet industry, an approach that we will follow for the remaining parts of this book.