Firms in several markets attract consumers by offering discounts in other unrelated markets. This promotion strategy, which we call "cross-market discounts," has been successfully adopted in the last few years by many grocery retailers in partnership with gasoline retailers across North America,...

Advertising to a consumer moves her further along the purchase journey, and tracking the consumer's online activities enables the advertiser to infer her purchase journey stage and target her accordingly. However, many consumers dislike being tracked, and repeated advertising leads to ad...

Digital advertising markets are growing and attracting increased scrutiny. This paper explores four market inefficiencies that remain poorly understood: ad effect measurement, frictions between and within advertising channel members, ad blocking and ad fraud. These topics are not unique to...

While millions of products are sold on its retail platform, Amazon.com itself stocks and sells only a small fraction of them. Most of these products are sold by third-party sellers, who pay Amazon a fee for each unit sold. Empirical evidence clearly suggests that Amazon tends to sell high-demand...