We examine the intersection of two major trends at online retail platforms: the emergence of retail media, which allows sellers to advertise on retail platforms alongside selling their products, and the platforms' switch away from reselling towards marketplace formats. We study whether and when...

We study the optimal algorithm decisions of a platform on ranking products sold by sellers--who may use fake sales to boost the rankings of their products--and the impact on consumers and sellers. We design a model of an online retail marketplace with competing sellers. The platform decides...