Like many other media services, internet search services provide two-sided platforms that coordinate interactions between media consumers and media advertisers. As with other media services, especially newspapers, the possibility has been raised that positive feedback between the consumer and...

We provide a model of television advertising based on an explicit characterization of an advertisement's contribution to an advertiser's profits that suggests that each program faces a downward sloping demand for its ad time. Hence Fournier and Martin's (1983) "law of one price" does not hold in...