What should Airbnb's key north star metrics be?

Focus on identifying metrics that capture the core value Airbnb delivers to its users, both hosts and guests. Consider metrics that reflect user engagement, satisfaction, and retention, such as the number of bookings per user, average length of stay, or repeat booking rate. Discuss how these metrics align with Airbnb's overall business goals, like growth in new markets or enhancing user experience. Be prepared to justify your choices by linking them to specific user behaviors and the company's strategic objectives, while also considering potential trade-offs between different metrics.