Share of Voice: Measuring Search Market Share

Why Share of Voice matters for B2B SEO

Classic SEO metrics such as rankings or organic traffic show your own performance in isolation. They don't answer the strategically decisive question: How big is my share of the search market compared to the competition? This is where Share of Voice (SoV) comes in. The metric translates visibility into a relative market share and so puts SEO in terms that management and marketing leadership can work with.

The link to market share has a basis in business economics. In classic media planning, the concept "share of voice correlates with share of market" describes the observation that a brand's share of advertising pressure foreshadows its market share over the long term. Applied to organic search, this means: if you hold a high share of visibility across a keyword set, you are more present in that topic area and tend to win more qualified demand.

In the DACH region, this presence is almost entirely tied to Google. In Austria, 81.87% of the search engine market goes to Google, followed by Bing with 9.01% and DuckDuckGo with 2.75% (StatCounter, May 2026). With 95.3% internet penetration and 8.69 million internet users (DataReportal, January 2025), Google visibility is effectively the same as the digital visibility of a topic. In practice, SoV measures your share of exactly this market.

The effort pays off especially in B2B. 81% of B2B marketers rate SEO leads as higher quality than PPC leads, and SEO leads close at a rate of 14.6% compared to 1.7% for outbound marketing (SEO Sherpa, international data 2026). A high SoV in the relevant purchase-stage keywords therefore means access to the highest-quality lead channel.

Share of Voice vs. Visibility Index vs. market share

The three terms are often mixed up, but they measure different things.

Share of Voice (competitive): SoV is always relative. It measures your own estimated organic visibility against the total visibility of a defined competitor and keyword set. Without a basis for comparison, there is no SoV. Semrush defines SoV as a measure of how much organic search visibility a brand captures compared to competitors, and gives an example: if the tracked keywords generate an estimated 100,000 clicks per month and your site captures 6,000 of them, your SoV is 6% (Semrush, 2025).

Visibility Index (absolute): The SISTRIX Visibility Index is an absolute index number per domain, not a percentage share. SISTRIX evaluates one million keywords with 100 results each, which makes 100 million data points, weighted by search volume and the expected click probability of the organic position, and has calculated this value daily since 2016, with a methodology unchanged since 2008 (SISTRIX, 2025). In our editorial view, the index is the de facto reference for search visibility in the DACH region. It only becomes SoV when you divide your own index value by the sum of the index values of a competitor set.

Market share (economic): A company's actual market share by revenue or volume. SoV is an indicator of it, but not a substitute. A brand can have a high SoV with a low market share (good SEO, weak conversion) or the other way around.

How Share of Voice is calculated

The formula always follows the same four-step principle, regardless of the tool.

1. Define the keyword set: A fixed list of relevant search terms for which SoV is measured. This set is the reference base and must not change unnoticed between measurements.
2. Weight each keyword by search volume: A high-volume keyword contributes more to SoV than a niche term. Without volume weighting, a top ranking for an irrelevant keyword would count just as much as one for a revenue-critical keyword.
3. Apply position-dependent CTR: Each ranking position is multiplied by its expected click probability. Position 1 gets far more weight than position 8. According to an international analysis, the top 3 results capture 68.7% of all clicks (First Page Sage, cited by Ahrefs, 2026), which is why the CTR curve drops steeply.
4. Account for SERP features: Featured snippets, local packs, or shopping boxes shift the click distribution. Semrush factors this in explicitly: the estimate accounts for keyword rankings, search volume, SERP features, and expected click-through rates per position (Semrush, 2025).

These four factors produce a weighted, estimated share of clicks. The basic formula is: your own estimated organic clicks divided by the total estimated organic clicks of the keyword set, expressed as a percentage.

Measuring SoV in the tools

Three tools dominate SoV measurement in the DACH region, each with a different approach.

Semrush Position Tracking: Here you set up a specific keyword set and a list of competitors. From these, Semrush calculates a percentage "Visibility" or Share of Voice value using the methodology described above, with rankings, search volume, SERP features, and position-dependent CTR (Semrush, 2025). The advantage is full control over the keyword and competitor set.

Ahrefs Rank Tracker and Brand Radar: Rank Tracker delivers classic SoV values for tracked keywords. Brand Radar extends the view to brand presence, increasingly in AI answers as well. This lets you think of SoV beyond the classic SERP, in the direction of AI visibility.

SISTRIX Visibility Index: SISTRIX doesn't provide a direct SoV percentage, but absolute index values per domain based on 100 million data points recalculated daily (SISTRIX, 2025). You build the SoV yourself by dividing your own index value by the sum of the index values of all relevant competitors. Its strength is broad, standardized market coverage in the DACH region.

One important caveat: all three work with estimates based on modeled CTR curves, not with your real click data.

Best practices: a valid keyword and competitor set

The quality of an SoV value stands or falls with the set. These principles are worth following.

• Align the keyword set with business goals: Include only terms with real business potential. A bloated set full of irrelevant keywords dilutes the value.
• Separate brand and non-brand: Brand keywords produce an artificially high SoV. For statements about the competition, the non-brand set is what counts.
• Choose a realistic competitor set: Not the largest corporation, but your actual search competitors. In B2B, these are often specialized providers, not industry giants.
• Freeze the set: For trend comparisons, the set has to stay stable over time. Every change breaks comparability.
• Cross-check with your own data: Tool SoV is an estimate. Validate it against reality from Google Search Console and GA4.

The reality check is central. Google Search Console provides real impressions, clicks, and average positions for your domain. If your actual share of clicks deviates sharply from the tool estimate, the tool's CTR assumption usually doesn't match your reality, for example because of AI Overviews or atypical SERP layouts. GA4 adds what happens after the click: engagement, conversions, and ultimately the organic channel's contribution to revenue.

Common mistakes and limitations

SoV is powerful, but easy to distort. The typical pitfalls:

• Estimation bias: Tool values are based on modeled CTR curves, not real clicks. When the SERP reality changes, the model lags behind.
• Keyword set bias: A set that overemphasizes your own strengths produces flattering values. Topics that matter to competitors are then systematically missing.
• Device and location dependency: SERPs differ by device and location. An SoV measured in Vienna doesn't automatically apply to all of Austria or the DACH region.
• Missing brand/non-brand separation: If you don't strip out brand keywords, you significantly overestimate your competitive SoV.
• Zero-click blindness: Classic SoV assumes that good rankings lead to clicks. That link is eroding.

The last point is the most serious. 60% of all Google searches ended without a click in 2025, up from 58% in 2024 (SEO Sherpa, international data 2026). A high SoV can therefore go hand in hand with declining real traffic when the SERP delivers the answer itself.

AI Overviews change what SoV tells you

The biggest structural change comes from AI answers in search. They increasingly decouple ranking from clicks.

Their prevalence fluctuates but remains relevant. According to an international analysis, AI Overviews were triggered for 6.49% of queries in January 2025, for 24.61% in July, and for 15.69% in November (Semrush, 2025, 10 million+ keywords). The impact on clicks is substantial: when an AI Overview is present, the average CTR of the top-ranking page is 58% lower (Ahrefs, 2026, 300,000 keywords, December 2023 vs. December 2025).

CTRs are falling outside of AI as well. The CTR at position 1 dropped from 28% (2024) to 19% (2025), a decline of 32%, and at position 2 from 20.83% to 12.60%, a drop of 39% (GrowthSRC, 2025, 200,000+ keywords). A US consumer study shows the behavior directly: with an AI summary, users clicked on a traditional result in only 8% of visits, compared to 15% without a summary, and on a link inside the AI answer itself in only 1% of visits (Pew Research, n=900 US adults, March 2025).

The consequence for SoV: a click-based SoV underestimates visibility that happens in AI Overviews without generating a click. That is why a new, complementary metric is taking hold: the AI Answer Inclusion Rate, or AI visibility. It measures the share of relevant queries in which your brand or your content appears or is cited in the AI answer. Tools such as Ahrefs Brand Radar are moving in exactly this direction. In practice, B2B companies should track classic SoV and AI visibility in parallel from 2026 on.

SoV as a KPI in SEO reporting

As a reporting metric, SoV shows its value through the trend, not the single value.

• Benchmarking: Measure SoV once to establish your starting position against the top competitors.
• Targets: Define specific SoV targets per topic cluster, for example "non-brand SoV in cluster X from 12% to 20% in twelve months".
• Trend analysis: Monthly or weekly trends instead of snapshots. If your SoV rises while competitors fall, market shares are shifting.
• Deriving SEO ROI: Link SoV gains to clicks from Search Console and conversions from GA4 to show the economic contribution.

Important for managing expectations in reporting: building SoV takes time. Only 1.74% of newly published pages reach the top 10 for at least one keyword within a year, and 72.9% of top 10 pages are more than three years old (Ahrefs, 2026). Set your SoV targets for the medium term accordingly.

DACH specifics and a B2B workflow

Several particularities come together in Austrian B2B. The near-total Google dominance of 81.87% (StatCounter, May 2026) lets you reduce SoV to Google in practice. At the same time, many B2B niches have low search volume. Here SoV becomes statistically unstable, because individual keyword movements make the percentage swing sharply. The solution is a deliberately narrow but business-relevant keyword set, and accepting that absolute positions for niche terms are often more meaningful than a volatile SoV percentage.

Local SERP features such as the Local Pack shift SoV regionally. If you measure in Austria against competitors from across the DACH region, define the location of the measurement explicitly.

SoV delivers the most value when you translate it into action:

1. Identify content gaps: Keywords in the set where competitors have a high SoV and you don't rank point to missing or weak content.
2. Prioritize competitive gaps: Tackle topics with high search volume and a large SoV deficit first, because that is where the lever is biggest.
3. Check the SERP reality: Before you act, find out whether a keyword still earns clicks at all or is dominated by AI Overviews.
4. Measure success: After you act, validate the change in SoV against Search Console and GA4 data to reconcile estimate and reality.

This turns Share of Voice from a pure reporting number into an operational management tool that gives concrete direction to the content roadmap and competitive strategy in DACH B2B.