Facebook Page Insights explained: the metrics that actually matter
Facebook hands you dozens of metrics and hides others behind the API. Here's what each one really means for an agency, which to report, and why some show as 'unavailable'.
Facebook Page Insights is a firehose. Your client doesn't need all of it — and some of what you might want to report, the API simply won't give you. Knowing which metrics mean something, and which are missing by design, saves hours and protects your credibility.
Reach, impressions and views are not the same thing
Reach is the number of unique people who saw a post. Impressions is the total number of times it was shown — one person can generate several. Views usually refers to video plays. Conflating them inflates your numbers and eventually gets noticed. Report reach for 'how many people', impressions when frequency matters.
Engagement is a rate, not a trophy
Raw likes look impressive on a big page and meaningless on a small one. Engagement rate — interactions divided by reach — tells you whether content actually resonated. A small account at 8% is doing better work than a large one at 1%, and clients understand that framing quickly.
The metrics Facebook won't give you
Not everything in the old Insights UI is available through the API, and some legacy metrics have been deprecated. When a metric can't be retrieved, an honest tool says 'unavailable' — because a zero looks like failure when it's really just missing data.
- Organic reach is available per post, but some historical windows are not.
- Certain photo and video view breakdowns are limited or deprecated in the current API.
- Paid reach lives in the ad account, not the Page — it has to be fetched separately.
What to actually put in a client report
Lead with reach and engagement rate, then the two or three posts that drove the month — with the creative. Separate organic from boosted, and label anything unavailable rather than hiding it. Three clear numbers beat thirty noisy ones.
How Castessa handles it
Castessa pulls the metrics the Graph API actually supports, labels anything unavailable instead of faking a zero, and separates organic from boosted — so your Facebook reporting is both complete and honest.
Part of our agency reporting guide