Cities can teach us about building platforms by understanding how they maximize connections between people. Cities enable a high degree of connectivity, which is essential for creating value through increased interactions between consumers and producers. The number of connections in a group increases exponentially as the total number of people in the group grows. This is why cities and platforms are similar, as they both create value in proportion to their ability to maximize connections. Cities, like platforms, develop their own gravity fields that attract resources, people, and companies into their orbit, leading to growing inequality between global megacities and smaller domestic cousins. The key to successful platform development is to listen to the "promenaders" and adapt to the needs of your community. Platforms, like cities, are ultimately about people, not just physical infrastructure or efficiency. By focusing on people and creating a balance between personal and physical aspects, platforms can succeed in a similar way that cities do.