How would you measure the success of Facebook Portal?

Focus on identifying key performance indicators (KPIs) that align with the goals of Facebook Portal. Consider both quantitative metrics, such as user adoption rates, engagement levels, and retention rates, as well as qualitative measures like user satisfaction and feedback. Discuss how you would gather data through surveys, usage analytics, and customer interviews. Additionally, think about the importance of comparing these metrics against industry benchmarks and how they tie back to Facebook's broader objectives. Be prepared to explain why you selected specific metrics and how they would inform product decisions moving forward.