Click-Through Rate (CTR)
The percentage of ad or email impressions that result in a click, indicating creative and targeting relevance.
“Is this creative and audience combination compelling enough to earn a click?”
Whether creative and targeting are relevant enough to prompt initial interest.
Whether the click leads to any meaningful business outcome — CTR is easily inflated by clickbait creative or accidental mobile taps.
Numerator
Clicks
Denominator
Impressions
Example
A display campaign serves 500,000 impressions and earns 4,500 clicks. CTR = 4,500 / 500,000 = 0.9%.
Recommended visualization: Line chart by creative variant
Use viewable-impression-based CTR (not served impressions) where the platform supports it, to avoid inflating denominators with unseen ads.
- Exclude known bot/invalid traffic per platform's IVT filtering
- Confirm impressions and clicks are pulled from the same attribution window
- Optimizing creative purely for CTR, which can reward misleading messaging and hurt downstream conversion quality
- Comparing CTR across placements with very different ad formats (native vs. banner) as if they were equivalent
Get a conversational, stakeholder-friendly explanation of this KPI, generated on demand.