Share of voice (SOV)

SOV counts what fraction of a results page you occupy: weighted by position, split organic versus paid, tracked across a keyword basket. It captures what rank #4 alone cannot — whether the page belongs to you, to one dominant rival, or to fragmentation, and whether your paid spend is buying presence or duplicating organic wins.

Two working uses: competitive tracking (a rival's SOV surge across your basket is a launch or budget offensive announcing itself days before it hits your sales) and cannibalization audit (high paid SOV exactly where organic SOV is already high = paying for slots you own — shift budget to terms where presence is actually missing).