CTR (Click-Through Rate) is the ratio of the number of clicks on an ad or link to the number of its impressions. It tells us what percentage of the people who saw the ad decided to click it.
Definition and formula
CTR = (number of clicks / number of impressions) × 100%
Example: an ad was shown 10,000 times and received 200 clicks. The CTR is 2%.
Where is CTR measured?
CTR is a universal metric — used in many contexts:
- Search ads (Google, Bing) — what percentage of people who saw the ad clicked it
- Display and social media ads — the effectiveness of a banner, a sponsored post, a video ad
- Email marketing — what percentage of recipients clicked a link in the message
- Organic results in Google — CTR also measures how effective a page’s title and meta description are at attracting clicks from search
What does a high or low CTR mean?
CTR tells you whether an ad or piece of content is attractive enough to prompt the user to act. A high CTR means the message resonates with the audience and encourages clicks. A low CTR can signal that the ad is not very relevant, not very engaging, or is reaching the wrong audience.
There is no single good CTR — its value depends on the channel, the format, and the industry. The CTR of search ads is usually higher than that of display ads, because the user is actively looking for something. CTR in email marketing is a completely different measure than CTR of a Facebook ad.
CTR and ad quality and cost
CTR has a direct impact on campaign costs. As we describe in the article on CPC — ad platforms convert every ad to impressions. An ad with a high CTR generates more revenue for the platform from each impression, which allows it to achieve a lower cost per click. In Google Ads, CTR is one of the components of the Quality Score, which directly affects an ad’s position and its CPC.
Is a high CTR always good?
Not necessarily. A high CTR with a low conversion rate means the ad attracts clicks, but the landing page or offer doesn’t meet the user’s expectations. That’s why CTR should always be analyzed together with conversion and CPA — only together do they give the full picture of campaign performance.
Summary
CTR is the percentage of people who clicked an ad or link after seeing it. The higher the CTR, the more effective the ad message — and the lower the potential cost per click. But a high CTR without conversions means nothing. CTR is one piece of the puzzle, not the only measure of a campaign’s success.
