In Langenfeld in North Rhine-Westphalia, the city centre has become a unique testing ground for ideas: retailers, citizens, policymakers, public administration, businesses and universities are all working together on future concepts for the retail trade and attractive, liveable city centres. One important element is the ‘city key’: anyone in possession of this mini chip who buys something in participating shops, restaurants or service businesses receives bonus points credited to an account. This makes parking cheaper when shopping, for example. Customers can use a wireless card to open the barriers to public parking facilities; their usage is settled by direct debit. At the same time, stationary retail is promoted with a wide variety of digital measures.