Diagnose a Meta CPA spike fast
The Meta CPA-spike sequence: events first, frequency second, auction third.
IntentWhy Meta CPA jumped: pixel, fatigue, auction, or edits.
- 4
- Steps
- 3
- Tools
- 2
- Rules
- 1
- Failure modes
When to use it
Use it when
- CPA jumped beyond noise on meaningful spend.
Do not use it when
- No specific contraindication beyond the preconditions below.
What it needs first
Required
Preconditions
- The account is ticked in the dashboard, confirmed via list_accounts.
Inputs
window- Analysis window.Default: last 30 days.
Procedure
In order. Every tool named is one the gateway ships, and links to its reference.
Split spend vs conversions on the spike.
Check pixel and event volumes.
Read frequency and CTR trends for fatigue.
Check the activity log for optimisation changes.
Decision rules
The observable condition, what it lets you conclude, and what takes the conclusion back.
When
Event volume fell account-wide while traffic held
Conclude
Measurement first: the spike may be invisible conversions, not expensive ones.
When
Frequency high and CTR decaying on the spenders
Conclude
Fatigue: route to creative-fatigue with the ad sets named.
Evidence every conclusion must carry
- Every figure carries its account, metric and window.
- Anything below a readable sample size is reported as unjudged, not as zero.
Where the agent stops
- The readout changes nothing. Any change it motivates goes through Safe Writes: preview, human confirmation, then apply.
How it goes wrong quietly
The cases where the analysis is wrong and still looks right. Read them before trusting a number.
- iOS and consent modelling shifts move reported CPA without reality moving: check for platform reporting notices in the period.
What the answer contains
- 01Readout
- The figures, with windows and accounts named.
- 02Flags
- What deserves a deeper skill or a human decision.