Click-Through Rate (CTR)
The percentage of impressions that generate a click.
Click-through rate is the share of displayed ads, links, or search results that receives a click. It helps diagnose whether a message and placement encourage the next action. In advertising and search, the denominator is impressions; email platforms can use a different definition, so check the report.
Example: A SaaS ad receives 20,000 impressions and 400 clicks. Its CTR is 2%. A second ad gets 600 clicks from the same number of impressions, reaching 3%. That gives the team a reason to investigate the second creative, alongside its downstream signup and customer quality.
Watch out: A curiosity-driven headline can improve CTR while reducing purchase intent. Compare ads within similar audiences, placements, devices, and objectives. Search position and branded versus nonbranded queries also affect CTR. Do not compare an email recipient click rate directly with an advertising impression click rate, or assume the most-clicked advertisement earns the most revenue.
Further reading: Google Ads: clickthrough rate.
Related: CPC, conversion rate.