To measure success for Facebook Events, I would use a combination of quantitative and qualitative metrics. Firstly, I would look at user engagement metrics such as the number of people creating events, the number of people attending events, and the number of people sharing events with their friends. These metrics would help me understand how engaged users are with the platform and whether they find it useful for discovering and attending events. Secondly, I would look at user satisfaction metrics such as surveys and feedback from users. This would help me understand how users feel about the product and whether there are any pain points or areas for improvement. Thirdly, I would look at business metrics such as revenue generated from events and partnerships with event organizers. This would help me understand whether the product is generating revenue and whether it is a valuable platform for event organizers. Overall, a successful Facebook Events product would have high user engagement, high user satisfaction, and generate revenue for the company.