Axel Sierau has worked in sports marketing and merchandising since the 1990s. He has lectured on topics related to sports economics, marketing, and event management. Sierau played handball from a young age and has coached university teams. Merchandising originated with branded merchandise like Mickey Mouse in the 1960s and soccer scarves in England. It grew in the 1980s as Manchester United pioneered branded merchandise strategies. Now every professional sports club has a merchandising program. Co-creation involves fans in the creation and sharing of brand value through emotional connections to their teams. It is based on principles of service-dominant logic where customers co-create value through resource integration.