Some important factors to consider when optimizing Facebook Ads Manager: Engagement, Frequency, CPMs, CTR, CPR, ROI, etc. These stats have a relationship with one another. Your CPMs (Cost per Millie) effects how much money you need to spend to garner impressions. Your CPR (Cost per Result) is directly related to how much money you've spent. Your Frequency and engagement rate will affect CTR (Click Through Rate) and understanding how all of these factors work will help you make informed decisions when optimizing your account. Remember, your bottom line is CONVERSIONS!