Müller, a popular retail chain, had a functional shopping app, but it wasn’t driving significant sales growth with customer loyalty cards. They aimed to incentivize bonus card usage, focusing on increasing app installations and encouraging customers to use the cards to collect points. The initial idea was to offer card bonuses with every order, which would lead to higher-tier bonus cards with more advantages and special discounts, assuming this would be a strong motivator. However, early testing revealed a more complex picture.