What Is Share of Voice?
Share of voice (SOV) is a competitive benchmarking metric that measures the proportion of the total available marketing exposure that your brand captures relative to all other brands in your category.
The concept originated in traditional media planning, where share of voice referred to the percentage of total advertising spend your brand commanded in a particular media channel.
Today, SOV is measured across paid advertising impressions, organic search visibility, social media mentions, PR coverage, and even AI citation frequency.
The formula at its simplest is: your brand's exposure divided by total category exposure, multiplied by 100. If your brand appears in 4,000 out of 20,000 total Google Ads impressions in your category per month, your paid search SOV is 20%.
If competitors account for the remaining 16,000 impressions, they collectively own the other 80%. Understanding this distribution tells you how visible your brand is versus the competitive field at any given moment.
Share of voice matters because of its proven link to future market share.
Research by the Institute of Practitioners in Advertising, building on work by Jon Stewart and Les Binet, demonstrates that brands with a share of voice greater than their current share of market (called excess share of voice or ESOV) tend to grow their market share over the following one to three years.
Conversely, brands with a lower SOV than their market share tend to shrink. This finding, while originally documented in traditional media, holds across digital channels in South African market data as well.
Share of Voice In Practice
The scenario below is an illustrative example, not a Juicy Designs client result. The figures indicate the scale of effect that share of voice work typically produces, so treat them as indicative rather than measured.
Picture a Pretoria-based short-term insurance broker spending around R80,000 per month on Google Ads for keywords like "car insurance quotes South Africa" and "home insurance Pretoria". An impression share audit (impression share is Google's own version of SOV) might show the broker holding something in the region of 18% of the available impressions.
Competitors, including two major insurers, would then be taking the remaining 80% or so of visible impressions. By restructuring the campaign, improving quality scores, and shifting budget from low-intent keywords to high-intent local queries, a broker in this position could plausibly grow its impression share to around 35% without increasing budget.
Lead volume might then rise by around 40% over the following quarter, because a larger share of the searches that matter is being captured at the same spend.
For South African businesses on tighter budgets, growing SOV does not always require increasing ad spend. Organic channels provide a powerful lever.
Publishing high-quality content that ranks for category keywords, building a consistent social media presence, earning media mentions through PR, and generating positive customer reviews all contribute to organic SOV.
A brand that is heavily present in Google's organic results for relevant searches, featured in industry publications, and mentioned frequently across social media captures attention even from consumers who never see a paid ad.
This blended approach to share of voice is especially effective for small and medium South African businesses competing against larger incumbents with bigger advertising budgets.
Share of voice and market growth
Share of voice measures a brand's presence in advertising or media relative to competitors, traditionally the proportion of category advertising a brand accounts for. It matters because of a well-established relationship in marketing: brands whose share of voice exceeds their share of market tend to grow, while those whose voice is below their market share tend to decline, as the gap, sometimes called excess share of voice, predicts change in market share over time. The logic is that consistently having a larger share of the conversation than your current market position builds the awareness and salience that win future customers. This makes share of voice a forward-looking indicator: investing to hold a share of voice above your market share is, in effect, investing in growth, while under-investing quietly cedes ground.
Measuring share of voice
Share of voice is calculated as your brand's presence divided by the total across you and your competitors, expressed as a percentage, within a defined channel and period. Traditionally it measured advertising spend or media presence, but the concept now extends across channels: share of paid search impressions, of organic visibility for target keywords, of social conversation, or of overall media mentions, depending on what you want to track. The key is defining the scope, which competitors, which channel, which period, and measuring consistently so comparisons are fair. Read as a trend against competitors, it shows whether your presence is growing or shrinking relative to the market, which, given the link between share of voice and future market share, is a useful early signal of where your brand's position is heading.
FAQ
How is share of voice calculated?
Share of voice is calculated by dividing your brand's total exposure (impressions, mentions, ad spend, or search visibility) by the total exposure of all brands in your category combined, then multiplying by 100. For example, if your brand has 3,000 monthly social mentions and the category total is 15,000, your social share of voice is 20 percent.
What is the relationship between share of voice and market share in South Africa?
Research by Nielsen and Les Binet shows that brands with a share of voice higher than their share of market tend to grow market share over time. South African brands that maintain excess share of voice, spending proportionally more on awareness than their current market share would suggest, consistently outperform competitors in long-term revenue and customer acquisition.
What is the relationship between share of voice and market share?
There is a well-established link: brands whose share of voice exceeds their market share tend to grow, while those below tend to decline. The gap between the two predicts future market-share change, which is why holding a share of voice above your current market share is effectively investing in growth.