Facebook’s ad relevance diagnostics
- Quality ranking: how the ad’s perceived quality compares with ads competing for the same audience.
- Engagement rate ranking: how its expected engagement compares with those ads.
- Conversion rate ranking: how its expected conversion rate compares with ads that have the same goal.
Each is shown as above average, average or below average.
The same idea elsewhere
Google Ads has Quality Score and ad relevance, and search engines judge how relevant every page is to a search. The principle is the same everywhere: the closer your ad or page matches what people want, the better it performs and the less it costs.