The thesis studies a specific form of strategy of digital platform, so-called “proeminence” or proeminent referencing. Proeminence is understood as the preferential treatment on platforms of goods/services/content to coax the choice of consumers. A proeminence strategy has similar consequences to bundling practices, it does not however necessarily constrain the consumer into buying another product. Firms use this lever to alter the decision process of consumers, with consequences to the competitive process, reducing the contestability of markets. Using a static formalism and a dynamic formalism, the thesis demonstrates how a firm, vertically integrated or not, may, using proeminent referencing, elevate barriers to entry et increase its profit beyond competitive levels. This effect is demonstrated through a simulation model and illustrated on a real world case of study : the Apple-Google Deal, for the default use of the Google Search Engine on the products using Apple‘s operating systems. Remedy proposal conclude this research study, looking to limit the negative competitive effect of these strategies.