Most owners know roughly how many customers they have. Far fewer know what an average customer actually contributes — and that single figure changes how you think about winning one, keeping one, and what you can afford to spend to get one.
The calculation
Take a business with annual sales of £300,000 across 60 customers.
£300,000 ÷ 60 = £5,000 per customer per year
If a typical customer stays for three years, that is around £15,000 of revenue over the relationship.
What that changes
It changes how you think about winning a customer. It also changes how you think about losing one.
Suppose 10% of those customers leave each year. That is six customers, and at £5,000 each:
6 × £5,000 = £30,000 of annual sales to replace before the business grows by a single pound
Most growth conversations focus almost entirely on winning new customers. Retaining the ones you already have is often just as valuable, and it usually gets far less attention and far less budget.
Putting acquisition cost in perspective
Knowing the lifetime figure also changes what “expensive” means.
If a customer generates £15,000 of revenue over three years and the business earns a 45% gross margin:
£15,000 × 45% = £6,750 of gross profit over the relationship
Against that, spending £500 to acquire a customer looks very different from judging it against their first invoice. Many businesses underspend on marketing because they are comparing the cost to the wrong number.
Two cautions on that. The gross profit is earned over three years, not up front, so acquisition spending has a cash flow cost before it has a profit benefit. And the three-year assumption is exactly that — an assumption.
An average can hide a lot
This is the important caveat.
If one of those 60 customers generates £60,000 a year, that single relationship represents 20% of total sales. The £5,000 average does not tell you that. It actively conceals it.
So it is worth looking at the customer list as well as the average:
- How much of your turnover comes from your largest customer?
- How much from your top five?
- Are there customers generating revenue but very little profit once the work is accounted for?
That first question is a risk question. A business where one customer is 20% of sales is a different proposition to one where the largest is 4%, even if turnover and profit are identical.
Revenue is not the same as value
A customer generating £20,000 a year at a 15% margin contributes less than one generating £8,000 at a 50% margin. If your margin varies by customer or service, the revenue-based figure can point you towards exactly the wrong customers to pursue more of.
Where you can, look at gross profit per customer rather than revenue per customer.
Three useful questions
- What is your average annual revenue per customer?
- How long does a customer typically stay?
- How many customers did you lose last year, and what revenue went with them?
Most businesses can answer the first. Far fewer can answer the third, and it is usually the most revealing.
Why it is worth the effort
None of these calculations is complicated. The value is in knowing the numbers, and in knowing which way they are moving.
Together with your margin, break-even point, debtor days and cash runway, this gives you a picture of the business that the annual accounts simply cannot provide — because by the time they are prepared, the year is over.
Compliance is important. Understanding your numbers is where the real value lies.
If you would like help putting your own figures against any of this, book a consultation.
