Click-through rate

Every few years somebody publishes a table of average click-through rate by position, and it gets quoted as though it were a law. It is an average over an enormous mix of query types, and the variance inside it is larger than the differences between the rows.

What an impression counts is looser than it sounds. Search Console records an impression when a result appears on the page a searcher was shown — which for a result at the bottom of a long page may mean it was never actually seen. A page whose CTR looks catastrophic is sometimes a page whose impressions are inflated by appearances nobody scrolled to.

Position explains less than the results page does. Ranking first under an answer box that already resolves the query is a different outcome from ranking first with nothing above you. The position is identical; the clicks are not. This is the single biggest reason a CTR benchmark fails to transfer between sites.

Where it is genuinely useful is as a diagnostic. A page ranking well with a CTR far below its own historical average has usually had something appear above it, or has a title and description that no longer match the query it is winning. Both are findable, and both are fixable without touching the ranking.