You're the GM of Google Photos preparing a one-page document. What key metrics would you include?

Focus on identifying metrics that reflect user engagement, retention, and growth for Google Photos. Consider both quantitative metrics, such as daily active users (DAU), monthly active users (MAU), and storage usage, as well as qualitative metrics like user satisfaction scores or Net Promoter Score (NPS). Highlight metrics that show how users interact with the product, such as the number of photos uploaded per user or the frequency of sharing features. Additionally, think about metrics that could indicate the success of new features or updates, such as feature adoption rates or the impact on churn. Be prepared to justify why each metric is critical for understanding the health and performance of Google Photos.