Share of Voice vs Share of Market: Differences, Formula & ESOV (2026)

Share of Voice (SOV) measures a brand's visibility, while Share of Market (SOM) measures the sales it captures. Looking at both metrics together helps marketers evaluate whether their current marketing investment is aligned with their business goals.

This guide explains how they differ, how they're connected, and how the gap between them can inform growth decisions.

What is Share of Voice?

Share of Voice (SOV) measures your brand's visibility compared to competitors over a specific period. It shows how much of the overall conversation or exposure your brand owns across channels like paid advertising, search, social media, and PR.

Formula:

Share of Voice (%) = (Your Brand's Metric ÷ Total Market Metric) × 100

The metric depends on what you're measuring, such as brand mentions, ad impressions, or keyword visibility.

For example, if your brand receives 2,500 mentions in a month and the entire market receives 10,000, your SOV is:

SOV = (2,500 ÷ 10,000) × 100 = 25%

This means your brand accounts for 25% of the total visibility in your market.

Types of Share of Voice

• Paid SOV: Measured using impression share in platforms like Google Ads.

• Formula: (Your Ad Impressions ÷ Total Available Impressions) × 100

• SEO SOV: Measures your share of organic search visibility across target keywords.

• Formula: (Your Keyword Clicks or Visibility Score ÷ Total Category Keyword Clicks or Visibility) × 100

• Social SOV: Measures your share of brand conversations on social media.

• Formula: (Your Brand Mentions ÷ Total Category Brand Mentions) × 100

What is Share of Market?

Share of Market (SOM) measures the percentage of total sales or revenue your business captures within a specific market over a given period. It shows how much of the market your brand actually owns based on customer purchases.

The formula is:

Share of Market (%) = (Your Brand's Sales or Revenue ÷ Total Market Sales or Revenue) × 100

For example, if your company generated ₦50 million in annual sales and the total market generated ₦500 million during the same period:

SOM = (₦50 million ÷ ₦500 million) × 100 = 10%

This means your brand holds 10% of the total market based on sales.

While Share of Voice measures how much visibility or attention your brand receives compared to competitors, Share of Market measures your actual share of sales or revenue. A higher Share of Voice can contribute to a higher Share of Market over time, but the two metrics are not the same.

SOV vs. SOM: Key differences 

While the table highlights their differences, the real value comes from understanding how the two metrics work together over time.

How are Share of Voice and Share of Market related?

Share of Voice (SOV) and Share of Market (SOM) measure different aspects of brand performance but are closely connected. SOV reflects a brand's current visibility, while SOM reflects the sales it has already captured.

As visibility increases, awareness and consideration typically grow before translating into purchases:

SOV ↑ → Awareness ↑ → Consideration ↑ → Purchase Intent ↑ → SOM ↑

For example, a personal care brand increases its SOV from 20% to 35% while maintaining a 20% SOM, resulting in a 15-point ESOV. Over the following months, awareness and sales rise, and its SOM gradually increases to about 22.5%.

This illustrates two key points: market share growth usually lags visibility, and sustained, consistent marketing is needed for higher SOV to translate into higher SOM.

What is Excess Share of Voice (ESOV)? 

Excess Share of Voice (ESOV) is the difference between a brand's Share of Voice (SOV) and Share of Market (SOM).

ESOV = SOV − SOM

A positive ESOV means a brand's visibility exceeds its current market share, while a negative ESOV means its visibility is lower than its sales position.

Example:

• Share of Voice: 30%

• Share of Market: 20%

• ESOV: +10 points

A positive ESOV indicates that a brand's visibility is exceeding its current market position. When maintained over time, this additional visibility can create the conditions for market share to increase. Nielsen's analysis of FMCG brands found that a sustained 10-point ESOV was associated with about 0.5% additional market share growth per year on average.

However, this is a directional benchmark, and actual results depend on factors such as industry, competition, and campaign execution.

What conditions affect whether ESOV actually drives growth?

ESOV is most likely to drive market share growth when several factors align. Research by Binet and Field shows that visibility alone is not enough.

Growth is more likely when:

• The market is highly competitive: ESOV works best in established categories where brands compete heavily for attention.

• Creative quality is strong: Advertising must be clear, memorable, and consistent.

• Campaigns achieve sufficient reach and frequency: The right audience needs to see the message often enough.

• The brand is differentiated: Extra visibility has more impact when the brand offers clear reasons to choose it.

• Consumers are responsive to advertising: ESOV is less effective in markets where buyers rarely switch brands.

• The investment is sustained: Long-term visibility is more likely to translate into lasting market share gains.

• Competitors don't match your spending: If rivals increase their own SOV, your ESOV advantage can quickly disappear.

What are the limitations of Excess Share of Voice?

While ESOV is a useful growth indicator, it has important limitations:

• Diminishing returns: After a certain point, additional visibility yields diminishing returns because most of the target audience has already been reached.

• Delayed impact: Market share often changes months after SOV increases, making it difficult to attribute growth solely to ESOV.

• Category complexity: In fragmented markets with many competitors, ESOV is harder to sustain and measure accurately.

• Digital vs. offline differences: Most ESOV research is based on traditional media, so results may be less predictive when offline factors heavily influence purchases.

• Short measurement periods: ESOV is a long-term metric. Measuring results over a few weeks or a single quarter can produce misleading conclusions.

These limitations mean ESOV should be viewed as a strategic indicator rather than a guaranteed predictor of market share growth.

How do you measure Share of Voice in practice?

The best way to measure Share of Voice (SOV) depends on the channel:

• Paid advertising: Use impression share on platforms like Google Ads and Microsoft Advertising. For cross-platform SOV, combine impression data across platforms.

• Organic search: Measure visibility across a defined keyword set using SEO tools such as SEMrush or Ahrefs. Google Search Console provides data for your site but not for competitors.

• Social media: Track your share of brand mentions with tools such as Brandwatch, Sprout Social, or Mention.

• PR and earned media: Use media monitoring platforms such as Meltwater or Cision to measure your share of press and news coverage.

Whichever method you use, keep your definition of the total market consistent. Changing the keyword set, competitor list, or measurement tool can shift the baseline and make trend comparisons unreliable.

How should you use SOV and SOM together?

Used together, SOV and SOM provide a clearer framework for marketing and budget decisions than either metric can on its own. 

1. Determining investment strategy: Comparing SOV and SOM helps businesses decide whether their marketing investment is sufficient to achieve growth goals, replacing guesswork with measurable insight.

2. Compared to competitors: The two metrics also allow companies to benchmark their visibility and sales performance against competitors, ensuring they are not under- or over-investing in the market.

3. Equilibrium: Over time, brands tend to move toward an equilibrium where SOV and SOM align. However, sustained differences between the two, either over-investment or under-investment, are what ultimately drive changes in market share.

What's the modern alternative to traditional SOV?

The modern measurement of Share of Voice has evolved to reflect better how consumers actually discover and engage with brands today.

1. The most widely used modern alternative is Share of Search, which measures how often people search for a brand compared to competitors and is strongly linked to future market share.

2. A broader alternative is Share of Attention, which measures how much overall attention a brand receives across channels like search, social media, video, and website traffic, focusing on real engagement rather than just exposure.

What are the most common mistakes marketers make with the SOV and SOM metrics?

The most common mistakes marketers make with Share of Voice (SOV) and Share of Market (SOM) stem from a misunderstanding of what each metric represents and how they work together.

1. Treating SOV and SOM as the same thing: Some marketers confuse visibility with sales performance. SOV measures attention and presence, while SOM measures actual revenue or market share. Mixing the two leads to incorrect conclusions about performance.

2. Using SOV without a clear definition of “voice” doesn't work; it only works when the metric is clearly defined, such as impressions, ad spend, search visibility, or brand mentions. Comparing inconsistent data sources makes the results unreliable.

3. Focusing only on total SOV instead of relative position: What matters is not just how much SOV a brand has, but how it compares to its Share of Market. Ignoring this relationship can hide underinvestment or overinvestment.

4. Expecting immediate results from SOV increases is unrealistic: SOV influences future market share over time. Many marketers expect short-term sales spikes, but the effect is usually gradual and delayed.

5. Ignoring quality of reach and engagement: High SOV driven by low-quality impressions or irrelevant audiences does not translate into SOM growth. The effectiveness of SOV depends on reaching the right audience with strong messaging.

6. Overlooking competitive reactions: SOV gains are not isolated. Competitors often adjust their own spending, which can reduce or neutralize the advantage if not monitored.

7. Using SOM as a short-term performance metric: SOM changes slowly and is influenced by long-term brand strength. Judging campaigns too quickly based on SOM alone can lead to poor decisions.

Why Share of Voice and Share of Market work best together

Understanding the relationship between Share of Voice (SOV) and Share of Market (SOM) helps marketers make smarter investment decisions. Comparing the two shows whether a brand is investing enough to strengthen its competitive position or simply maintaining its current performance.

Viewed together, SOV and SOM provide a clearer picture than either metric alone. The gap between them helps marketers assess whether their current marketing investment supports long-term growth or requires greater visibility to remain competitive.

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