This thesis focuses on how specific aspects of product differentiation affect economic outcomes through their impact on competition between firms. The first paper presents an analysis of firms’ incentives to share information about the perceived profitability of different technologies prior to making an investment decision. The model is one of vertical product differentiation in which firms face uncertainty over consumers’ preferred product. The main result is that firms reveal information only when they are sufficiently uncertain about which investment strategy to pursue. Information can be revealed in order to facilitate either coordination on a particular technology or anti-coordination on different technologies. In the second paper a seller can choose to sell one or several horizontally differentiated products from competing developers. Developers can charge the seller different wholesale prices for their products where prices are dependent on whether the seller will also carry a competing product. A higher consumer valuation of products raises the potential market share from a single product and thereby increases competition between developers. This implies developer profits can decrease in product quality. The model is compared to a situation in which developers compete for consumers without an intermediary seller. This comparison illustrates how developers sometimes can make higher profits by using a downstream seller since the seller’s pricing response acts as a competition softener between developers. In paper three the focus is on product allocation through a single developer of several products who can decide how to allocate them among sellers. This model also features horizontally differentiated products but introduces multidimensional consumer preferences over products and sellers. The developer’s product allocation decision is shown to be a key profit determinant for the supply chain. By distributing different products to each seller, the developer can focus inter-seller competition on the product dimension of consumer preferences. Distributing the same products to both sellers allows the developer to force sellers to compete in the dimension of consumers’ seller preferences. The relative intensity of consumer preferences over products and sellers thereby determines a profit maximizing allocation for the developer.