After you launch your ads, you need to monitor and optimize your performance. This is the process of measuring and improving your results based on your goal and metrics. You can use Facebook's tools to track and analyze your ad performance, such as impressions, reach, clicks, conversions, or revenue. You can also use Facebook's tools to test and optimize your ads, such as split testing, dynamic creative, or automatic placements. Split testing allows you to compare different versions of your ads to see which one performs better. Dynamic creative allows you to combine different elements of your ads, such as images, videos, headlines, or texts, and let Facebook optimize the best combination for each audience. Automatic placements allow you to let Facebook choose the best places to show your ads, such as Facebook, Instagram, Messenger, or Audience Network.