Of many standard contemporary business or marketing metrics, B2C or B2B, Market Share (MS) is one of the most ubiquitous.
Growing, retaining or defending MS is a corporate mission most employees understand instinctively, and can rally behind. After all, isn’t outdoing your competitors in a given market an obviously desirable business outcome to prioritise?
Moreover, marketing doesn’t happen in a vacuum. As the word implies, it is the discipline of pricing, placing and promoting products or services in specific channels within a competitive market.
Shouldn’t all marketers therefore seek a correct understanding of their target market, including its key competitors – and then to steal from their MS?
In this article we review the data needed to compute MS, historical and contemporary academic research into using MS as a metric, and some of the real-world practical challenges it poses.
We then consider how MS targets may not be equally valuable goals for all enterprises, and how the appealing siren song of MS can distract private sector marketers from their underlying mission: to help their employer maximise returns for its shareholders.
“Show Me The Numbers”
Those with practical experience of reviewing or analysing MS within businesses, as well as academic commentators, know how critical it is to understand deeply what can and can’t, or what should or shouldn’t, form part of MS maths.
For those lacking such experience, the most fundamental question is whether to measure MS by value or volume – a key strategic consideration, especially if achieving or maintaining high volume share requires profit-eroding price reductions.
Beyond baseline value vs volume of goods or services sold, other measurement approaches exist.
These include Customer-Based MS, measuring the absolute number of customers acquirable in a market – for example in subscription-driven B2C business models, or in B2B niches with a finite number of potential account to win; and Relative MS, measuring share performance against that of specific competitors.
Across all these binary baselines, a more nuanced challenge is what to include in, or to exclude from “the market” – and why.
Regular MS strategy commentator Glen Berg helpfully lists the 6 necessary definition dimensions: competitors, products, sales channels, geographic areas, customers, and time periods.
- For example, knowing a manufacturer’s volume share of the total Connected TV market in Germany would likely be immaterial, if their business strategy is to produce only large screen size, UHD models with a 4-figure expected sales price as a minimum.
- Similarly, quantifying a brewer’s share of the total on-trade beer market in Wales could be wasted effort, if total beer demand in Wales is shifting significantly to off-trade, and on-trade share focus diverts attention from the larger industry dynamic.
Fixing the definition of the market in which an organisation intends to target MS is of course only half the challenge. The other half is securing the data needed to thereafter size the market – of sufficient quantity, quality and timeliness.
In B2C, especially in the Consumer Packaged Goods (CPG) and Fast-Moving Consumer Goods (FMCG) sectors, it is common for companies to buy in regular “Panel Market” data from providers of Retail Panel Market data such as Gfk/NIQ or Gfk/YouGov (Europe), or NPD/Circana (US).
Directly-equivalent B2B sources are available, but are by definition very limited in the product categories for which they can track sales data. For example, Gfk/BOSS provide Office & Stationery insights within the context of the wider Business Supplies market.
In enterprises procuring Retail Panel Market data, significant financial and time resources are invested in its analysis to track MS performance – among other objectives. Data is supplied weekly, monthly, biannually or annually, via large bespoke chart packs, spreadsheets, and online platforms.
(This author has worked for an enterprise that habitually invested an 8-figure € sum annually on such procurement. This sometimes led, counter-intuitively, to “analysis paralysis” whereby swift, efficient marketing decision-making could be actively hampered by an unwillingness to use anything but the very latest market data as a reference).
These data sets entail another computational conundrum: their “coverage” of any given market.
Point of Sale (POS) data underlies Retail Panel Markets, which aside from consistency and quality considerations across retailers, has other important coverage dimensions.
For example, many retailers only sync full sales data sets monthly, whereas some Panel Market clients require weekly feeds. Thus, weekly data can “cover” fewer POS, and therefore require greater extrapolation to build a total market understanding.
Moreover, many B2C brands don’t supply Panel Market suppliers with 1st party sales data. So, competitors seeking insight into, for example, Apple’s laptop market share in southern Belgium in the last 6 months, don’t know how much of the total market Apple’s substantial Retail and eCommerce businesses generate – fundamentally obfuscating the coverage ratio.
The overall takeout of these quantitative considerations is clear: accurately calculating MS is more complex than it may appear to the inexperienced eye.
The Academic View
One of the most-cited academic foundations of MS theory is the 1975 Harvard Business Review (HBR) article “Market Share: A Key to Profitability” (Buzzell, Gale & Sultan) in which the authors propose a positive correlation between MS and Return On Investment (ROI) across their sample set, and that as market share increases, a business is likely to generate higher profits (fig. 1)
Figure 1. Image source: Harvard Business Review
The word “correlation” is a key element. “Correlation” ≠ “Causation”, as the article itself notes.
This has led to decades of debate over whether MS is a meaningful marketing metric. BCG’s Bruce Henderson in a 1989 HBR article characterised MS as “malarkey”, and more recently in 2006 a thoughtful Wharton article went further, in characterising MS as a flawed, “competitor-oriented” metric that actively distracts from profit maximisation.
So, in 2025 – do the academics believe marketers should Care about Share?
The unsurprising answer is that their debate continues. For example, a thought-provoking 2016 MIT Sloan article by professors Neil Bendle and Charan Bagga advises against using MS as an ultimate objective, and even being cautious about using it as an intermediate metric (fig. 2)
Figure 2. Image source: MIT Sloan Management Review
For contemporary marketers, 50 years on from the world in which Buzzell, Gale & Sultan’s seminal HBR article was launched, we agree with professors Bendle and Bagga that MS should be viewed with increasing caution as a marketing metric.
Not only does the long-established “correlation / causation” challenge of linking MS to profit generation persist to this day, but the contemporary curve of digital technologies adoption by both customers, and by suppliers in any given market, can greatly impact putative links between MS
growth and profit growth.
A European-originated 2024 HBR article argues convincingly that across 824 measured enterprises, the 3 traditionally-suggested drivers of such links – Efficiency, Market Power and Quality Perception – are all today significantly distorted by their competitive “digital transformation” status (fig. 3):
Figure 3. Image source: Harvard Business Review
The authors’ premise is that how much marginal MS growth can actually boost profits, is linked to marginal digital capability growth.
The more digitally-advanced an enterprise, the less that MS gains can translate into profit gains. Even small enterprises can nowadays successfully boost profits through digital drivers of Efficiency (e.g. automated workflows) and Quality Perceptions (e.g. careful curation of online reviews) without
needing MS gains to achieve this fundamental corporate goal.
Conclusion
MS as a day-to-day marketing and business metric is of course not going away, and large enterprises used to procuring expensive data to aid complex rolling MS calculations are unlikely to change any deeply-embedded, related marketing practices.
However, we believe the marginal profit-generating value of using MS as a marketing or business metric is shifting away from such larger enterprises.
It is for small, digitally-evolving CPG/FMCG brands, who may previously have lacked the resources to access Retail Panel Market data, that starting to buy it in can be the greatest game-changer.
They can use it not only as a source of new, trackable competitive data, but as a culture change catalyst. It can inform not only downstream marketing, but also upstream New Product Development, with objective real-world insights into consumer preferences across the 6 definition dimensions of the markets in which they compete.
Growing, retaining and defending MS isn’t – and perhaps hasn’t been for a long time – an ultimate objective of itself. Beware the siren’s song!
