The European Youth Card offers discounts on culture, travel, accommodation, shopping, and services in most European countries. Anyone under the age of 30 or 26 , depending on the country, can purchase one for under \(€ 20\). Typically effective for one year, there are three versions: a classic card, a student card, and a co-brand card, the latter issued by a specific firm or local government. What is the main motivation for firms to offer discounts to holders of these cards?