Two firms produce a product with a horizontal and a vertical characteristic that we call quality. The difference in the quality levels determines how the firms share the market. Consumers do not observe quality before purchase. Under non-comparative advertising a firm signals its own quality,...

Does advertising revenue increase or diminish content differentiation in media markets? This paper shows that an increase in the technically feasible number of ad breaks per video leads to an increase in content differentiation between several thousand YouTube channels. I exploit two...