What to remember
- Define category, geography, period and channels before calculating.
- Separate value market share from volume market share.
- Do not confuse ESOV, a point difference, with MSAR, the SOM-to-SOV ratio.
- Treat the gap as a signal to investigate rather than guaranteed growth.
Align scopes before comparing
Media share of voice is the brand’s media spending divided by total category media spending. Market share is the brand’s sales divided by total market sales, measured by value or volume.
A defensible comparison requires the same category, geography, period, channels, brand portfolio and currency. Social mentions or search visibility are not substitutes for a media-spend share.
- Same category
- Same geography and period
- Same brand portfolio
- Stated channels and currency
- Value or volume SOM identified
Calculate four measures with different meanings
SOV = brand media spend ÷ total category media spend × 100. Value SOM = brand revenue ÷ total category revenue × 100. Volume SOM uses units instead of revenue.
ESOV = SOV − SOM and is expressed in percentage points. MSAR = SOM ÷ SOV and is a ratio. A difference and a ratio are not interchangeable.
| Measure | Formula | Permitted reading |
|---|---|---|
| SOV | Brand spend ÷ category spend × 100 | Relative media weight |
| SOM | Brand sales ÷ market sales × 100 | Relative commercial weight |
| ESOV | SOV − SOM | Percentage-point gap |
| MSAR | SOM ÷ SOV | Commercial-to-media weight ratio |
Read an example without inventing a forecast
Illustrative example: a brand spends €12m out of €60m in its category, giving 20% SOV. It generates €90m of sales in a €600m market, giving 15% value SOM. ESOV is +5 points and MSAR is 0.75.
These results describe a relative position at a stated time. The five-point gap is not a market-share forecast, and more spending does not automatically create growth.
| Input | Value | Result |
|---|---|---|
| Media spend | €12m / €60m | SOV 20% |
| Sales | €90m / €600m | SOM 15% |
| Gap | 20% − 15% | ESOV +5 points |
| Ratio | 15% ÷ 20% | MSAR 0.75 |
Interpret the relationship within its limits
Research documents a relationship between share of voice and market share in some markets and periods. Lars Bech Christensen also shows that category advertising intensity and competitive structure alter that relationship.
Creative quality, reach, distribution, pricing, innovation, brand size and channel fragmentation remain outside the raw calculation. ESOV can support a budget hypothesis, not establish causality or a universal threshold.
Move from the signal to the decision file
The inspected Calc catalogue includes an MSAR calculation defined as market share divided by advertising share of voice. This convention remains separate from ESOV. The page claims no public execution, automatic input from Mix or Grid, or autonomous budget recommendation.
Retain denominators, sources, dates, coverage assumptions and tested scenarios. The decision may then concern a test, maintenance or conditional reallocation, with an owner and review date.
Frequently asked questions
Are SOV and share of mentions the same?
No. SOV here means share of media spending. Mentions, impressions, searches and citations require separate measures and denominators.
Does positive ESOV guarantee market-share growth?
No. It describes a relative investment gap. Observed relationships vary by brand, category, channel, period and execution quality.
Should SOM be measured by value or volume?
Use the unit that matches the decision and keep it throughout the comparison. They may diverge when price and mix differ.
What if SOV is zero?
The MSAR ratio needs an explicit convention. Do not turn no investment into an automatic mathematical or strategic conclusion.
Full sources
- Lars Bech Christensen, share-of-voice/share-of-market relationships, complete scientific paper PDFComplete source available online · Read the complete source
- Nielsen, definition and scope of media share of voice, complete articleComplete source available online · Read the complete source
- Nikki Clarke, Nielsen, SOV-SOM relationship across 123 brands and 30 categories, complete articleComplete source available online · Read the complete source
- IPA, current limits of ESOV in a fragmented media environment, complete articleComplete source available online · Read the complete source