What Byron Sharp Got Right That Most B2B Marketers Still Get Wrong
Five laws from marketing science, and why the evidence suggests most organisations are yet to act on them.
Most B2B marketing strategies are built on a comfortable but largely unsupported idea: that the path to growth runs through your existing customers. Deepen loyalty. Grow share of wallet. Turn advocates into referrers. Byron Sharp's How Brands Grow arrived over a decade ago and methodically dismantled that assumption using empirical research across thousands of brands.
The core argument has held up. The adoption rate has not kept pace. A 2024 audit of $9.4 million in B2B LinkedIn ad spend found that 32% was being directed at audiences with no ability to buy [1]. That is not a targeting problem. It is a strategic one, and it is precisely the problem Sharp's work was written to solve.
What the research actually shows
Sharp and his team at the Ehrenberg-Bass Institute analysed buying patterns across thousands of brands and found that growth follows a small number of predictable laws. Not theories. Laws, in the sense that they replicate consistently across categories, markets, and time periods.
The most disruptive finding: brands grow by acquiring more buyers, not by increasing loyalty among existing ones. Even large, dominant brands rely heavily on light, infrequent buyers. Loyalty programmes and retention-focused marketing are not wrong, but they are rarely the primary driver of revenue growth.
What drives growth instead? Two things: mental availability and physical availability.
The two levers that actually move the needle
Mental availability means being the brand that comes to mind when a buyer enters a category. Not being differentiated in a clever or niche way, but being distinctively recognisable across a wide range of buying situations. Sharp's argument is that distinctiveness matters more than differentiation.
Being recognisable beats being "meaningfully different" if your market rarely thinks of you at all.
Physical availability means being easy to buy. In B2B terms, that means being present in the right procurement frameworks, on the right shortlists, through the right channels and partnerships, and discoverable at the point of need.
The third law is the one B2B organisations find hardest to act on. Research from the Ehrenberg-Bass Institute, conducted with the LinkedIn B2B Institute, found that only 5% of B2B buyers are in-market at any given time [2]. Companies change service providers roughly every five years on average, which means 95% of your target market is not yet ready to buy.
Narrow targeting strategies that focus only on accounts actively purchasing right now structurally miss the vast majority of future revenue. Broad reach, built over time, creates the mental availability that converts when a buyer finally enters the market.
Where organisations misread Sharp
"Broad reach" does not mean undisciplined reach. It does not mean marketing to everyone or abandoning audience strategy. It means reaching everyone within your realistic market, and that requires a precise, shared definition of who that market is.
This is where Ideal Customer Profile (ICP) definition becomes foundational rather than administrative. Without a clear ICP, broad reach becomes diffuse spending. With a clear ICP, broad reach becomes a disciplined investment in building mental availability with the buyers most likely to generate long-term value.
At Magnus, this is the starting point for every growth conversation. Before we discuss channels, messaging, or spend, we work with leadership teams to establish a single, commercially grounded view of their best-fit customers: who they are, how they buy, and what moves them from awareness to decision.
The ICP is not a marketing tool.
It is the commercial foundation on which growth focus is built. The Magnus GTM Confidence Index 2025 found that 71% of leaders in siloed sales and marketing organisations report low confidence in hitting growth targets [3].
A shared, precise ICP is one of the primary mechanisms through which that alignment is created. When it is missing or fragmented, the Sharp principles cannot be applied effectively.
You cannot build mental availability if different teams disagree on whose attention you are trying to earn. You cannot achieve physical availability if you are not present in the right places for the right buyers, and you cannot grow by acquiring more buyers if no one agrees on which buyers you are targeting.
The bigger point
How Brands Grow is, at its core, an argument for thinking bigger and more clearly at the same time. Bigger in the sense of reaching more of the market, more consistently, over a longer horizon. Clearer in the sense of knowing precisely who that market is and designing your GTM to serve it.
The businesses that grow fastest tend to do both well. They have the clarity of a well-defined ICP and the discipline to build availability across that entire market, rather than harvesting only from accounts already in-market.
If your growth strategy leans too heavily on retention, or your targeting is narrower than your opportunity, it is worth revisiting the foundations before you revisit the budget.
Find out how Magnus helps B2B leadership teams define their ideal customer profile and build the commercial focus that growth requires.
Explore Defining Growth Focus →
References
- GrowthSpree (2024). "32% of B2B SaaS LinkedIn ad budgets are wasted on audiences that can't buy." Reported by MarketScale. Available at MarketScale.
- Dawes, J. / Ehrenberg-Bass Institute for Marketing Science (2021). "The 95:5 Rule: Why B2B Growth Starts Long Before the Purchase." LinkedIn B2B Institute. Available at Marketing Science Institute.
- Magnus Consulting (2025). GTM Confidence Index 2025. Read the report.