The position-to-click-through-rate mapping that powers visibility and share-of-voice calculations. Position 1 on Google captures ~28% of clicks, position 10 captures ~2%. Amazon and AI Overview surfaces have their own curves.

CTR curves

Why CTR curves matter

Ranking position alone is meaningless. The Theia visibility model converts every observed ranking into an expected click share using a position → CTR curve specific to the surface and country.

Position 1 on Google UK organic: ~28.5%
Position 2: ~15.7%
Position 5: ~5.0%
Position 10: ~2.4%
Position 20: ~0.5%

A product ranking at position 1 for one keyword is worth ~14× one ranking at position 10. Any visibility calculation that doesn't apply CTR weighting is materially wrong.

Surface-specific curves

CTR distributions are different per surface:

Surface	Position 1 CTR	Notes
Google organic (no AI Overview)	~28%	Classic SEO baseline
Google organic (with AI Overview)	~14%	AI synthesis halves below-fold clicks
Amazon organic	~35%	Higher concentration than Google
Amazon paid (top)	~12%	Lower than organic same position
AI Overview citation	~40%	High share when present

Theia maintains separate curves per country and updates them quarterly as the surfaces evolve. The recent AI Overview rollout shifted Google CTR curves materially — running on a 2022 curve overstates organic visibility by ~2×.

How it gets used

The visibility index for a product:

visibility(product) = Σ over keywords [ CTR(position_kw) × volume_kw ]

This is the click-weighted, volume-weighted measure of how much consumer attention a product captures across its competitive keyword set.

Share of voice is then this number divided by the same calculation summed across all products in the category.

Source of the curve

Theia's CTR curves blend:

Public CTR studies (Advanced Web Ranking, Sistrix annual reports)
DataForSEO observed CTR for live SERP positions
Client-provided GSC data (when available) for calibration

The blended curve is stored in data_store.ctr_tables as the single authoritative reference across the codebase.

Strategic implication

A correct CTR curve is the foundation of every meaningful visibility metric. Get it wrong and:

Your share-of-voice number is wrong
Your visibility-vs-conversion analysis is wrong
Your competitive ranking is wrong

The Bose Germany finding — that Bose converts generic traffic 10× better than Soundcore but captures 13× less of it — only emerges when both sides of the equation use the same correctly-calibrated CTR curve. With a wrong curve, the conversion gap disappears into the noise.

Related terms