Advertising, Search and Intermediaries on the Internet: Introduction
介绍在线中介如何通过广告盈利，并探讨中介、企业与消费者之间的复杂关系，为理解在线广告如何改变企业竞争和消费者搜索行为提供理论框架。
I wonder how many times you have already used a search engine, a price comparison website or a social networking site today? Such online intermediaries gain much of their revenue by offering advertising positions within their search results or on their websites. This form of advertising has evolved into a huge industry. The enterprise value of Google, for example, is now close to $140 billion.1 But far more than being just a big business, advertising within online intermediaries is fundamentally changing the way in which firms compete by altering how consumers search for information about products and prices. Such changes prompt many policy questions, but these questions can only be answered once economists have a better theoretical understanding of the complex interrelationship between intermediaries, firms and consumers. This feature aims to develop that understanding further. In particular, the five articles investigate how firms compete to pay an online intermediary for advertising slots, how consumers use the intermediary’s information within their search behaviour and how this, in turn, affects firms’ pricing decisions.