Explain why the cost structure associated with many kinds of information goods and services might imply a market supplied by a small number of large firms. Could lower transaction costs in e-commerce ever make it easier for small suppliers to compete? As noted in Chapter 3, network externalities are often an important aspect of demand for information goods and services. (The benefits to customers of using software, participating in electronic markets, or using instant messaging increase with the number of other users.) How might network externalities affect firm operating strategies (pricing, output, and advertising) and firm size?