According to Ben Thompson's Aggregation Theory, powerful Internet companies succeed by sitting at the nexus between consumers and suppliers. On one hand, these companies exclusively control the user experience / relationship and deliver a product (at zero marginal cost) that garners massive usage. On the other hand, suppliers flock to the Internet company to get access to the company’s millions (billions?) of users. What results is a virtuous cycle whereby an increasing number of users begets an increasing number of suppliers, and vice versa. Meanwhile, the aggregator is extracting the majority of value from the value chain.