With regards to the original post, I have to say there really isn't anything left but to echo a lot of what was said in a very concise way:
- Use the demographic and geographic targeting in Facebook, as well as take behavioral and contextual clues from Analytics, Search Console, and Google Ads to understand what they want to learn or do. Know who they are and how to speak to them. Deliver relevance.
- Leverage your CRM because you've spent the time to build the list, so you already should have some brand recognition. Create look-alikes from that list as well. Clean the list either manually or use a smart third-party like ePush.
- Test. Test. Test. You should test your graphics, language, headlines, everything. Multivariant testing is important, but don't change everything all at once. Be methodical. Learn what actually makes a difference. If you rush changes, you'll not pinpoint what drove the change.
- Measure. Measure. Measure. As everyone has said, there are a number of metrics to look at. When you identify the best performing and worst performing, analyze what their key differences were. Maybe the message was off? Maybe the targeting could've been more refined?
You can yield really good results from Facebook ads.