Not All Revenue Is Worth Chasing, and Your Growth Plan Should Say So
A manufacturer I'll leave unnamed spent 2 years and real marketing money chasing a new customer segment because it was "the future of the market." The segment bought. Revenue went up. Everyone felt good until someone finally ran the profit by segment and found the new business was earning almost nothing, while the boring segment they'd stopped calling was carrying the entire company. They had grown into their least profitable customers and starved their most profitable ones, and they'd done it on purpose, with a plan and a budget.
This is the most common growth mistake in the lower middle market, and it doesn't look like a mistake while you're making it. The top line moves the right direction. The trouble is that the top line is the one number that can't tell you whether growth is worth having.
The whale curve nobody plots
Rank your customers by profitability, add them up from most profitable to least, and plot the running total. The shape that comes back is so consistent it has a name. It rises steeply, flattens, and then, near the end, it bends back down.
The research behind that curve is blunt. Studies that fully allocate cost to customers routinely find the top 20 percent of accounts generate somewhere between 150 and 180 percent of total profit, while the bottom 20 percent destroy an amount equal to 50 to 80 percent of it. Put differently, a large slice of your customers are quietly taking back profit that the good accounts worked to earn. One academic synthesis of B2B studies found that roughly 30 to 50 percent of customers are unprofitable once every cost is properly assigned, not because they're bad people, but because their order patterns, payment terms, and service demands cost more than their margin covers.
Most owners have never seen this curve for their own business. They've seen revenue by customer, which slopes gently down and reassures you that everyone is contributing something. Profitability by customer is a different picture entirely, and it's the one that should drive where you point your growth.
Growth is an allocation decision, not a volume target
Once you can see the curve, "grow the business" stops being a useful instruction. The real question is which customers to grow, and the answer sits in numbers you can already pull.
New-business acquisition converts in the 15 to 25 percent range in most B2B selling. Selling more to a customer you already have converts at 40 to 60 percent. That gap is enormous, and it points somewhere specific: the cheapest, highest-odds growth in your company is usually deeper into the accounts already sitting at the profitable end of the curve. Those customers know you, trust you, and cost a fraction to sell because you're not paying to earn attention you already have.
Meanwhile the instinct to chase net-new logos, the ones that make a good story at the industry dinner, is often the instinct to buy revenue at the worst conversion rate and, if you're not careful about who you're courting, the worst margin too. Growth that adds customers who land in the bottom fifth of the curve isn't growth. It's you volunteering to lose money at scale, with enthusiasm.
What to do with the number once you have it
You don't need activity-based costing across the whole company to start. Take your top 30 accounts and your bottom thirty by revenue, assign the real costs to each, orders, freight, returns, payment lag, and the service hours honestly counted, and see where they actually fall. The pattern will announce itself well before the math is perfect.
Then aim the growth plan at the top of the curve. Put your best salespeople on expanding the profitable accounts, not defending the difficult ones. Build the marketing around finding more customers who resemble the ones already earning you money, because the fastest way to know your ideal customer isn't a workshop, it's the top decile of a profitability ranking you already have the data to build.
For the bottom of the curve, you have three moves and all of them beat ignoring it. Reprice the work so the account pays for what it costs. Redesign how you serve it so it costs less, a standing order instead of daily fire drills, a lower-touch channel instead of your phone. Or, for the handful that will never work at any price, let them go to a competitor and wish them the margin.
Firing customers sounds reckless until you've seen the curve. The counterintuitive finding across this research is that removing genuinely unprofitable accounts, or fixing their terms, can raise total profit even as revenue falls, because you stop subsidizing losses with the earnings of your best customers.
The plan that says "more" is not a plan. The plan that says which customers, at which end of the curve, and why, is the one worth funding. Build the curve first. It will tell you where your next dollar of effort belongs, and just as usefully, where it doesn't.