Boardroom Definition
Share of Voice (SOV) is a competitive metric that calculates the percentage of total advertising exposure a brand controls within its specific industry. Historically calculated based on media spend, it serves as a comparative measure of visibility: "How loud is our brand compared to the competition?" It is widely recognized as a leading indicator of Market Share as brands that consistently maintain a Share of Voice higher than their Share of Market tend to grow.
SOV is calculated as a ratio of brand activity to total category activity.
The Spend-Based Formula: SOV = (Brand Ad Spend / Total Market Ad Spend) * 100
The Impression-Based Formula: In digital environments where spend data is private, impressions are used as the proxy: SOV = (Brand Impressions / Total Market Impressions) * 100
The Growth Formula (ESOV): The relationship between SOV and growth is defined by Excess Share of Voice (ESOV): ESOV = Share of Voice - Share of Market
- Positive ESOV: The brand is investing aggressively and is predicted to gain market share.
- Negative ESOV: The brand is "quiet" relative to its size and is at risk of losing market share.
The Real Scoop
In the broadcast era, calculating SOV was simple: you bought a Nielsen report and saw who spent what on TV. In 2026, the fragmentation of digital media has made calculating a "Total SOV" nearly impossible.
The reality is that Digital SOV is a fractured metric. Because every user sees a personalized feed, there is no single "Total Market" to measure against. Consequently, smart planners have shifted from "Category SOV" (which is largely unknowable) to "Impression Share" within specific platforms. For example, in Google Search, you can see exactly what percentage of eligible auctions you appeared in. This is actionable data; chasing a nebulous "Global SOV" number is often a theoretical exercise that distracts from tactical execution.
Watch Outs
- The "Niche" Fallacy: It is easy to manipulate SOV by narrowing the category. Owning 100% SOV of "Blue Widgets in Zip Code 48201" looks impressive on a slide but is irrelevant if the broader market is buying Red Widgets globally.
- Quality vs. Noise: High SOV does not guarantee High Attention. A brand can achieve 80% SOV by flooding the market with cheap, low-quality banner ads. If competitors are running fewer, high-impact video ads, they may win the Share of Mind despite having a lower Share of Voice.
- Competitor Blindspots: Many SOV reports rely on public crawling tools that miss "Dark Social" or "Walled Garden" spend. Your report might say you are winning, while your competitor is silently dominating on a platform your tool doesn't track (e.g., WhatsApp or private Discord communities).
