Creative Fatigue Analysis Tool — illustrative example

INPUT
CTR falls while campaign spend expands into a new audience. No audience-level figures supplied.

RESULT
Observed: lower aggregate CTR coincides with a broader audience.
Alternative explanation: the changed audience mix may contribute to the decline.
Needed analysis: compare original-audience performance over time and review the new audience separately.
Conclusion: creative fatigue is not established by the supplied aggregate trend.

REVIEW
Declining performance can reflect audience, seasonality or measurement changes. Compare frequency, spend and conversion definitions before blaming the creative.

This is a teaching example, not a live execution record.