Hi Reader, A few weeks ago, we told you about free layover airport tours and how excited we were to do one in Beijing. This is how they work: If you fly with certain airlines and have at least 6+ hours at the airport, you get a free city tour! (Read our email about it here.) So we planned our flights accordingly and couldn't wait to see the Great Wall of China for free. 🤩 But sadly, we didn't manage to get on the tour! We knew there was limited capacity, but not that it would be limited to...