The “Excess Share of Voice” (ESOV) rule is as close to a law of marketing as we are likely to ever have. Across tens of thousands of marketing cases covering hundreds of markets and economic conditions, this rule is continually proved to be true.

Brands that maintain a higher share of voice relative to their size will grow. Brands with a low share of voice relative to their size will shrink.

Here's a simple illustration. Here we see a brand increasing its share of voice within the industry. 

"Share of voice" refers to not just the marketing or advertising spend of a brand, but its ability to occupy more of the content (and thus more of the mindshare) of its market.

As this brand increases its share of voice, its share of the market rises to restore equilibrium. 


Often, particularly in a recession, this argument is put forward by marketing experts as a basis to ensure that companies do not cut advertising spend and damage future growth prospects. Peter Field gave an excellent webinar on the subject recently.

Within Professional Services, the rule holds true, a firm that has a strong reputation in a particular discipline will likely get more business than a firm that does not. Indeed, the chart below, from marketing aX borders suggests that Professional Services are particularly sensitive to “Excess Share of Voice” (ESOV). The data shows that within professional services, market share adjusts much faster to equilibrium.


Can a firm grow a larger share of voice in the market whilst budgets are being cut? 

The tide has gone out across whole industries, with budgets being cut broadly across the board. Spending will be down generally, and so too will be marketing budget. Additionally, many of the ways in which law firms have promoted themselves to their clients in the past are simply not possible anymore. 

However, budgets being down and communications restricted by-and-large to digital makes growing share of voice possible, it just needs a change of approach. Within professional services, there is so much potential to do digital better. Competition online, particularly within the content space for share of voice is surprisingly low in professional services.

We found last year that in the UK, the average lawyer produces one piece of content per year. In the US, that number is just one piece of content every 2 years.



Also, clients are now hungrier than ever for certainty, for clarity and for the knowledge of their expert advisors. The opportunity is there for those knowledge-rich firms to capture a disproportionate share of the market.

Growth in market share will come to firms that can simply better use the knowledge and tools available to them to increase their share of voice in the digital space. 

Applying a fraction of the costs that were previously used to communicate in non-digital channels into enabling Professionals to communicate with their audience should deliver disproportionate returns.