Click-Through Rate (CTR)
Click-through rate is the percentage of recorded impressions that generate a counted click.
What is Click-Through Rate?
CTR relates clicks to opportunities to click. In advertising it often indicates how frequently an ad’s appearance leads to interaction. The relevant interaction may be any click or a specific link click, depending on the report.
CTR is not a percentage of shoppers who purchased. It ends at the click. What happens after the click belongs to metrics such as conversion rate, revenue per session and contribution from the resulting sales.
CTR (%) = Clicks ÷ Impressions × 100
Use matching click and impression definitions. If the report has no impressions, the percentage is undefined. A unique-email-click rate uses a different population and should not be silently substituted.
Interest in a running-shoe advertisement
An ad receives 80,000 impressions and 1,200 link clicks. Link CTR is 1.5%. If the report also records 400 other clicks on the ad, an all-clicks CTR would be 2%. Those values differ because the numerator includes different actions.
How to interpret it
CTR can help describe how well a message and placement attract clicks from the audience reached. A higher value can be useful when the clicks are relevant to the offer. It does not prove that the message creates profitable demand.
A provocative headline can attract many visitors who do not want the product. Conversely, an ad that clearly states the price may attract fewer but more qualified shoppers. Interpret CTR with post-click behavior rather than pursuing the percentage in isolation.
Changes in placement, device or audience can change CTR without a change to the creative. Compare stable segments when trying to understand whether a particular message improved. A store-wide blended percentage may conceal these differences.
CTR is impression-weighted. If two ads have very different impression counts, calculate the overall rate from their combined clicks and impressions. The simple average of their individual percentages is usually not the campaign total.
Common mistakes
Calling click-through a conversion
Unless the defined conversion action is the click itself, CTR is an earlier step. A purchase requires another measured event.
Ignoring the click type
All clicks may include actions that never take the shopper to the store. Link CTR and all-clicks CTR need different labels.
Definition reference: Google Ads: clickthrough rate.