CRO Glossary
Click-Through Rate vs Conversion Rate
CTR measures clicks on a link or ad, while conversion rate measures completed goal actions after the click.
This is a distinction, not a single metric, but it trips people up constantly: click-through rate (CTR) measures how many people clicked something (an ad, an email link, a CTA button), while conversion rate measures how many of those people went on to complete the actual goal — a purchase, signup, or download.
A campaign can have a fantastic CTR and a terrible conversion rate if the ad promises something the landing page doesn't deliver. For example, an ad offering "50% off everything" might pull in huge click volume, but if the landing page doesn't honor that offer clearly, conversion rate collapses even though CTR looks great.
In A/B testing, it's easy to optimize the wrong metric by accident. A headline change might boost CTR on a product card while actually reducing downstream purchases, because it attracted curious clickers rather than buyers. Always tie CTR improvements back to conversion rate (and revenue) before declaring a test a win.
Related terms
Above vs Below Median Split
A segmentation technique that divides users into two groups at the median of a metric to compare high and low engagers.
Qualitative Feedback Loop
A recurring process of collecting and acting on user comments, session recordings, and survey responses to inform test hypotheses.
Experiment Metadata
The structured record of who, what, when, and how for a test — hypothesis, owner, dates, variants, and metrics used to track and audit it.
Pre-Test Analysis
The upfront work of validating traffic, metrics, and baseline data quality before launching an experiment.
Above-the-Fold vs Below-the-Fold Messaging Hierarchy
How the order and prominence of value-proposition messaging is split between the visible screen and the rest of the page.
Experiment Contamination
When a control or variant group is unintentionally exposed to the other condition, corrupting the comparison.
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