My dissertation consists of three chapters in each of which I analyze how specific phenomena affect market competition and the firms’ strategic decisions. Below I briefly describe the findings of each chapter. The first chapter analyzes a situation where a firm’s customers learn some unanticipated or hidden use value of the firm’s product whereas the non-customers remain uninformed about that extra value. Should the firm advertise and inform all consumers about its product’s hidden value? A monopolist will benefit from advertising its product’s hidden value. However, our analysis reveals that this may not be true when the firm faces competition in the market—the firm may actually make higher profits if it keeps its hidden value secret from ...