In a particularly vibrant nightlife precinct of Shenzhen, in China, the main attraction may be a massive landlocked cruise ship that's been turned into hotels, bars and restaurants. But in its shadow, is an equally bizarre but less obvious novelty: a round structure that resembles a public restroom from afar, but on closer inspection is a 24-hour self-service beer stop where each tap's price changes based on demand. It's like playing the stock market, but your gains come in a giant plastic cup and your skill at pouring your brew of choice.