Simple:
- Make sure ads are placed in optimal positions, max 2 above fold
- Make sure content is good enough to pass google spot checks, content quality requirement scales as you generate more revenue
- Make sure your average user session > (30 - 60 seconds)
- Mobile friendly and fast loading important
- Make sure you're attempting to collect emails so you can re-market with newsletters
Then send FB clicks to website ad traffic to content. The formula above should return a positive ROI over 60 days from tier 1 FB traffic.