Click-Through Rate (CTR)

What is Click-Through Rate (CTR)?

CTR is calculated as clicks divided by sends (or impressions), expressed as a percentage. Of all the standard email and ad metrics, it has aged the best — clicks remain a clear, intentional action even as opens have been degraded by privacy fetchers and AI summarizers, and impressions have been inflated by mobile and AI surfaces. Healthy B2B cold-email CTR runs 2-5%; ad CTR depends heavily on placement and intent but generally sits at 1-3% for display and much higher for branded search. The right way to use CTR is comparatively — variant A vs variant B, this week vs last, our number vs the channel benchmark — rather than as an absolute target.

Why it matters

• Survives the death of the open as a meaningful signal — clicks are still real intent.
• The cleanest input to A/B testing — clicks vs clicks is an apples-to-apples comparison.
• Predicts downstream conversion well — high-CTR audiences convert disproportionately.

Use cases

• Subject-line testing. Two subjects, identical body and CTA; CTR picks the winner.
• Ad-creative ranking. Paid teams rank creatives by CTR before optimizing for cost-per-click.
• Page-level diagnostics. Low CTR on a page CTA suggests the page promise didn't match the click.