This chapter presents an introduction to this practice of in-game advertising (IGA): providing a definition, an overview of its benefits and drawbacks, and an outline of the industry-commissioned and academic research that has been conducted on its effectiveness. IGA concerns the incorporation of advertisements into the environment of a digital game, a practice similar to the integration of product placements in movies or television shows. IGA can take a lot of different forms, ranging from sponsorship deals to the use of real-world analogs brand placements branded music and sounds and branded characters. The limited capacity model of motivated mediated message processing (LC4MP) states that a person's ability to process information is limited, with people having access to only a limited pool of cognitive resources at a particular time. The LC4MP is, thus, of great importance when studying the player's ability to cognitively process the advertising messages that are integrated into a digital game.