Click-through Rate

Click-through rate (CTR) is the share of times an element was shown and then clicked: clicks divided by impressions.

CTR is an efficiency rate, not a count; its value is that it measures clicks against opportunity, so an element seen rarely but clicked at a high rate beats a much-shown, rarely-clicked one. The key to reading it right is the denominator: an impression must really mean seen, not merely loaded; if an element sits below the fold where users do not scroll, counting it as an impression drags CTR down artificially. The second trap is comparing CTR across different positions: the click rate of the first search result is inherently higher than the tenth, so CTR is only comparable within the same position and denominator. In SEO, CTR relates directly to position, and a sudden drop usually means the page's title or description is not compelling in results.