Share of Voice

In advertising, there is a persistent myth: more spending equals more results. Invest more in advertising, the logic goes, and you'll capture more market share. But the relationship between advertising spending and market share is not linear. It follows a curve—steep at first, then flattening, then eventually diminishing. This curve is captured in one metric: Share of Voice (SOV), and understanding it is critical to defending advertising budgets and understanding competitive dynamics.

Share of Voice is the percentage of total advertising spending in a category, by a brand, relative to all competitors. If a category has $100 million in annual advertising spending, and your brand spends $12 million, your SOV is 12%.

The relationship between Share of Voice and market share is well-documented: a brand's SOV roughly predicts its share of market (SOM). But the relationship has a critical nuance: the ROI on advertising spending follows an inverted curve. Spending below market share (underinvesting in SOV) leaves growth on the table. Spending at market share (matching competitors) maintains position. And spending significantly above market share (overinvesting in SOV) produces diminishing returns and is, ultimately, wasteful.

For growth-stage brands, the optimal SOV is 120–150% of market share. For mature brands, optimal SOV approaches market share. For declining brands, SOV must exceed market share to defend position. Get this wrong, and you're either wasting money or leaving share on the table.

What Is Share of Voice?

Share of Voice (SOV) is the percentage of total advertising spending (across all media, all competitors) in a category, attributed to a single brand.

Calculation:

SOV = (Brand Advertising Spend / Total Category Advertising Spend) × 100

Example:

Soft drink category, annual advertising spend:

• Coca-Cola: $400 million
• PepsiCo: $350 million
• Monster/Energy drinks: $200 million
• Dr Pepper/Snapple: $150 million
• All others: $200 million
• Total category spend: $1.3 billion

Coca-Cola's SOV = ($400M / $1.3B) × 100 = 30.8%

SOV can be measured across all media (TV, digital, print, outdoor, etc.) or by specific channel (SOV in digital advertising, SOV in social media, etc.).

Why It Matters

1. SOV predicts market share (roughly). Brands with higher SOV tend to have higher market share. The relationship is not 1:1 (spending efficiency varies), but it's strong. If Coca-Cola has 30% SOV, it will likely have somewhere in the range of 25–35% market share, depending on efficiency, brand strength, and distribution.

2. SOV growth predicts share growth. When a brand increases SOV faster than competitors, it tends to gain share. When a brand's SOV shrinks, its share typically shrinks. This is the primary mechanism by which brands grow in mature categories: outspend competitors on a percentage basis.

3. There is an optimal SOV for growth. This is critical. The relationship between SOV and market share follow an inverted U-curve:

Underinvesting in SOV (SOV < Market Share): Diminishing position. A brand with 15% market share but only 10% SOV is underinvesting relative to competition. It's losing to competitors who are outspending it proportionally. To grow share, the brand must increase SOV above its current market share.

Optimal SOV for growth (SOV = 120–150% of Market Share): A brand with 10% market share and 12–15% SOV is overinvesting relative to competition, but the ROI is high. This extra spending builds brand awareness, trial, and switching, driving share gains. The rule of thumb: growing brands should spend at 120–150% of market share.

Overinvesting in SOV (SOV >> Market Share): Diminishing returns. A brand with 10% market share but 25% SOV is wasting money. The incremental ROI on that extra spending is low. Additional awareness and trial don't translate proportionally to share gains because the brand is already top-of-mind and most consumers aware of the brand have already chosen to buy competitors or are price-sensitive. The curve flattens.

4. Saturation point is real. Beyond a certain SOV threshold (usually 20–25% in most categories), incremental advertising produces minimal ROI. This is why Coca-Cola, despite massive advertising budgets, doesn't see proportional returns at extreme SOV levels.

5. SOV is a proxy for competitive intensity. In high-SOV categories, advertising is expensive and competitive. In low-SOV categories, advertising is cheaper and less competitive. Understanding the category's SOV pattern tells you whether advertising is a viable growth lever.

The Practice: A Concrete Example

Consider the U.S. premium athletic footwear market: Nike, Adidas, New Balance, Puma, and others.

Market Dynamics (hypothetical but illustrative):

• Total U.S. market: $12 billion in annual sales
• Total category advertising spending: $1.2 billion (10% of sales is typical for premium footwear)

Nike:

• Market share: 35%
• Advertising spend: $480 million
• SOV: 40%
• Situation: Nike's SOV (40%) exceeds its market share (35%), meaning it's overinvesting by ~5 percentage points. This is typical for market leaders defending against challengers.

Adidas:

• Market share: 18%
• Advertising spend: $180 million
• SOV: 15%
• Situation: Adidas's SOV (15%) is below its market share (18%), meaning it's underinvesting. To grow share, Adidas would need to increase SOV to 20–25%. Alternatively, Adidas is efficient: it achieves 18% share with only 15% SOV, suggesting strong brand equity and distribution efficiency.

Puma (growth stage):

• Market share: 5%
• Advertising spend: $120 million
• SOV: 10%
• Situation: Puma's SOV (10%) significantly exceeds its market share (5%). This is the formula for growth: overinvest in SOV to drive trial and awareness. Puma is spending 2x its market share percentage in an attempt to gain share. If the advertising is effective, Puma should see share growth over 18–24 months.

The SOV-Share Relationship Over Time

Year 1: Puma increases SOV to 10% (while at 5% market share).

Year 2: Increased awareness and trial drive Puma market share to 6–7%, but category advertising spend also increases, potentially lowering Puma's SOV back to 8%. Puma must continue increasing spending to maintain growth momentum.

Year 3: Puma market share reaches 8–9%. At this point, Puma's optimal SOV would be 9–11% (120–150% of market share). If Puma can execute efficiently, share growth may continue.

Year 5+: If Puma becomes a strong #3 brand with 12–15% share, it should maintain SOV at 14–18% to defend position, but not significantly exceed market share (which would be wasteful).

Related Concepts

Thought Leaders and Key Research

• John Philip Jones (Syracuse University) – Foundational research on SOV and market share relationships
• Les Binet and Peter Field (Effie Awards, IPA) – Research on advertising effectiveness and SOV dynamics
• Keith Weed (Unilever) – Portfolio management and SOV across multiple brands
• Byron Sharp (University of South Australia) – Market share growth and advertising efficiency

Common Mistakes

1. Assuming SOV = SOM guarantee – SOV is predictive, not deterministic. A brand can have high SOV and underperform on market share if advertising is ineffective, brand equity is weak, or distribution is poor. Conversely, a brand with lower SOV but superior creative or brand strength may outperform.
2. Overinvesting in SOV beyond the saturation point – Many mature brands continue spending at high SOV levels out of habit or defensive posture, despite diminishing returns. As a brand approaches 20–25% share, the optimal SOV approaches market share. Spending beyond that is wasteful.
3. Confusing SOV growth with share growth – A brand can increase SOV (spend more) without gaining share if competitors also increase spending. If the entire category increases advertising 20%, all SOV percentages remain the same, but every brand's ad spend rose. Actual growth requires SOV growth relative to competitors.
4. Not accounting for advertising efficiency – Different ads have different effectiveness. A brand with 10% SOV and exceptional creative might outperform a brand with 15% SOV and mediocre creative. SOV is a baseline; execution matters.
5. Ignoring channel-specific SOV – SOV varies dramatically by media channel. A brand might have 15% overall SOV but 5% SOV in social media (where newer, digital brands dominate) and 25% SOV in TV (where legacy brands still spend heavily). Channel-specific SOV is often more relevant than aggregate SOV.
6. Failing to defend SOV against challengers – When a challenger brand enters a category with high SOV, market leaders often fail to match or exceed the new entrant's relative SOV. This allows the challenger to gain awareness and trial. Defending share requires maintaining superior SOV, especially in early phases of the challenger's entry.

FAQs

Q: What's a "good" SOV for my brand?

A: If you're in growth mode, SOV should be 120–150% of your market share. If you're in defend/maintain mode, SOV should match your market share. If you're profitable and mature, SOV can be at or slightly below market share. The ideal SOV depends on your strategic objective and competitive position.

Q: Can a small brand compete with low SOV?

A: Yes, with caveats. A small brand with strong creative, niche targeting, or distribution advantage can punch above its weight in terms of market share relative to SOV. Digital advertising is particularly efficient at driving small-brand growth with lower absolute spend. But all else equal, higher SOV enables faster growth.

Q: How do I calculate SOV if I don't know competitors' advertising spend?

A: Use industry data from Kantar, Nielsen, or company disclosure. Most large CPG and automotive companies disclose advertising spending in earnings reports or annual reports. Industry associations publish category data. Alternatively, estimate based on media mix: if you know TV and digital spending, you can infer category totals from industry reports.

Q: Does SOV matter more in some categories than others?

A: Yes. SOV matters more in low-differentiation, high-competition categories (beverages, fast food, consumer packaged goods) where advertising is a primary driver of share. SOV matters less in high-differentiation categories (luxury goods, B2B) where brand equity, distribution, and product quality dominate advertising efficiency.

Sources and References

• Jones, J. P. (1990). "When Ads Work: New Proof That Advertising Triggers Sales." Lexington Books.
• Binet, L., & Field, P. (2007). "Marketing in the Era of Accountability." Warc Publications.
• Sharp, B. (2010). "How Brands Grow: What Marketers Don't Know." Oxford University Press.
• IPA (Institute of Practitioners in Advertising). (2019). "The effectiveness of advertising and the role of share of voice."

Conan Pesci is a marketing strategist and writer focused on brand strategy, advertising effectiveness, and competitive dynamics. This entry is part of the Markeview Editorial Index.