Share of voice (SOV) is the proportion of all the visibility in your market that belongs to your brand, compared with competitors. It originally meant your share of total advertising spend or exposure in a category; in digital marketing it now covers several measures, including share of paid search impressions, share of organic visibility for a set of keywords, share of social conversation and share of search.
How share of voice works
The basic calculation is your brand’s measure divided by the total for the market, multiplied by 100. What changes is the measure:
- Advertising SOV: your media spend or impressions as a share of the whole category’s. This is the traditional version used for TV, radio and outdoor.
- Paid search SOV: in Google Ads, impression share tells you what percentage of eligible searches your ads appeared for, which makes it a close relative of SOV.
- Organic SOV: SEO tools estimate how much of the potential clicks for a tracked keyword set reach your site, based on rankings and search volume. These are modelled estimates, not measurements.
- Social SOV: your share of mentions or conversations about the category on social platforms, taken from listening tools.
- Share of search: searches for your brand name as a percentage of searches for all the brand names in your category. In the UK, the effectiveness expert Les Binet popularised this as a proxy for market share through work presented with the IPA, the trade body for advertising agencies.
Share of search is the easiest version for a small business to track at no cost. Use Google Trends, filtered to the United Kingdom, to compare your brand name with three or four competitors over the same period, then work out each brand’s slice of the combined interest.
Why it matters
Share of voice relates your activity to the market rather than only to your own past. Traffic that grew over the year sounds like good news until you notice competitors grew faster. A share measure cuts through that.
Advertising effectiveness research, much of it published through the IPA, has found that brands whose share of voice sits above their market share tend to grow over time, while those below it tend to shrink. The gap is called excess share of voice. It is a long-term, category-level relationship rather than a rule for any single campaign, but it explains why cutting all visible activity in a lean year can cost market share later.
Share of search is particularly useful as an early signal. Interest in a brand name tends to move ahead of sales, so a falling share can warn you before revenue drops.
Common mistakes
- Defining the market loosely. SOV against “all estate agents in the UK” means little to an agency in Bath. Choose the competitors your customers actually weigh you against.
- Treating tool estimates as fact. Organic SOV from SEO tools depends on the keywords you track and each tool’s click model. Use it for trends over time, not as a precise number.
- Blending different measures. Paid impression share, organic visibility and share of search answer different questions. Report them separately.
- Ignoring ambiguous names. If your brand name is a common word, share of search will be noisy. Add a qualifier or interpret it with care.
- Chasing share for its own sake. Buying impression share on expensive terms that do not convert raises SOV and loses money.
How to act on it
Pick a small, honest set of competitors: three to five businesses customers really choose between. Decide which SOV measures fit your goals. For most small UK businesses, share of search plus paid impression share covers the essentials.
Record a baseline, then check quarterly and watch the trend rather than any single reading. If your share of searches for branded keywords is slipping while a competitor’s grows, look at what they are doing differently: new advertising, press coverage, a new location or a pricing change.
Use what you find to balance short-term promotion with longer-term brand marketing. Setting that balance, and the measures to judge it by, is part of the digital marketing strategy and consulting I offer.