Click-through rate (CTR)
Clicks divided by impressions. Of everyone who saw the thing, the share who actually clicked it.
See it
What it is
CTR is clicks divided by impressions, shown as a percent. 40 clicks on 2,000 impressions is a 2% CTR. It is the fastest read on whether the thing people saw was interesting to the people who saw it, which makes it a joint score for creative and targeting at once.
Benchmarks only mean anything inside a placement. Search ads on a high-intent branded keyword can run 10% and up, because the person typed your name. Display and banner inventory often sits near 0.05%, and that is normal, not broken. The same metric shows up in email (clicks per delivered send) and in Search Console for organic results, so always say which CTR you mean.
Gotcha: CTR measures curiosity, not quality. A clickbait headline or a fake-discount image will lift CTR and tank everything downstream, and you pay for every one of those clicks. High CTR paired with a low conversion rate is the classic signature of an ad writing a cheque the landing page does not honor.
Ask AI for it
Build a CTR metric card component for a campaign dashboard. Show the headline number as a large percent with one decimal, the raw clicks-over-impressions fraction underneath in small muted text, a delta versus the previous period with an up/down arrow colored green or red, and a 14-day sparkline behind the number at low opacity. Add a faint horizontal benchmark band showing the placement's typical range so a number can be read as good or bad at a glance. Keep it compact enough to sit in a 3-across metric row.