We develop a model with many advertisers (products) and many advertising markets (media). Each advertiser sells to a different segment of consumers, and each medium has a different ability to target advertising messages. We characterize the competitive equilibrium in the media markets and...

We develop a model with many heterogeneous advertisers (products) and advertising markets (media). Each advertiser has a different consumer segment for its product, and each medium has a different ability to target advertisement messages. We characterize the competitive equilibrium in the media...