Glossary · SEO
CTR Decay Curve
also: SERP CTR curve · click-through-rate decay · position CTR distribution
Definition
The CTR decay curve describes how organic click-through rate falls as SERP rank position drops. Published curves from Sistrix, AWR, and Backlinko converge on roughly 28% to 40% CTR at position 1, dropping to single digits below position 5, with curve shape varying sharply by query intent.
The CTR decay curve is the most-cited empirical relationship in SEO. Position 1 typically captures between 27.6% (Sistrix 2020, all queries) and 39.8% (First Page Sage 2023, B2B commercial) of clicks; positions 2 and 3 each take roughly half the previous step, and beyond position 5 the share flattens into the long tail. The curve is not stationary: AI Overviews, featured snippets, and zero-click results have compressed the top of the curve since 2022 (positions 1-3 lose share to Position 0 and AI panels). Curve shape also varies by intent: transactional queries have steeper top-of-curve decay than informational queries, where users read multiple results.
Essays on this concept
- SEO
The Click-Through-Rate Decay Curve and SERP-Position Economics
How the empirical CTR-by-position curve has flattened at the top of the SERP, what the unit economics of moving from position 6 to 3 versus 3 to 1 actually look like, and where the diminishing returns sit in practice.
- Marketing Strategy
The Compounding Advantage of Content Moats: Modeling SEO as a Capital Investment with Depreciation Curves
A single well-written article generates traffic for years. That makes content a capital asset, not an operating expense, and like any capital asset, it depreciates. The companies that model this correctly build content moats that compound. The rest produce content that decays.
- SEO
The Topical Authority Audit: Measuring Coverage Without Counting URLs
How to measure topical authority by entity coverage and semantic completeness rather than by URL count, drawing on Bill Slawski's patent analysis, entity- based SEO frameworks, and the NLP literature.
Related concepts
Authoritative references