Share of Voice (SOV)
The percentage of category marketing presence owned by one brand.
Share of Voice (SOV) is the percentage of a category's total marketing presence — paid media impressions, organic search visibility, social mentions, or press coverage — attributable to a single brand. Excess SOV over market share is a leading indicator of future market share gain.
Context
The Ehrenberg-Bass Institute and IPA research established that brands whose SOV exceeds their market share tend to grow market share; brands whose SOV is below their market share tend to lose it. The optimal 'excess SOV' level is approximately 10 percentage points above current market share for sustainable growth.
SOV is calculated per-channel. Paid SOV (ad impressions in category), organic SOV (search rankings and visibility), social SOV (social mentions), and press SOV (earned coverage) all measure related but distinct dimensions.
A brand with 8% market share and 15% paid SOV is investing ahead of its current position — a setup typically followed by market-share gains over 12–24 months. A brand with 20% market share and 10% SOV is underinvesting and typically loses share.
SOV in the head category matters more than SOV in niche categories. A brand with 50% SOV in a tiny sub-niche but 5% SOV in the main category will lose share overall.