The One Number That Quietly Kills Businesses

Jim Collins has a framework called the Hedgehog Concept.

It's the intersection of three circles:

1. What you're deeply passionate about
2. What you can be the best in the world at
3. What drives your economic engine

More often than not, people building a business focus heavily on the first two. The passion. The craft. The thing they want to be the best at.

Few truly understand the third.

And the third is the one that determines whether the business actually survives.

Your economic engine is the foundation the entire business is built on. Get it right and everything else has room to breathe. Get it wrong and no amount of passion or talent will save you.

This is exactly what has caught so many e-commerce businesses out after the boom.

During COVID, there was a flood of disposable income in the economy, and a flood of time being spent online. As a result, acquiring a new customer online was the cheapest and easiest it had ever been. And that's where all the focus went.

Acquisition, acquisition, acquisition.

What most of them never built was a real understanding of their economic engine.

And as conditions have changed, the businesses with no engine underneath them have fallen apart.

I was reading an email this week from Dominic Iacovone, the founder & CEO of a billion-dollar brand portfolio, that crystallised this.

He made the case that the single most important metric in business is lifetime value divided by customer acquisition cost. And he's right to point at that relationship, because here's the thing about customer acquisition cost.

It only ever goes up.

When you start out, your acquisition cost is the lowest it will ever be. You're reaching the warmest, most obvious audience first. But as the business grows, that cost climbs in one direction only.

You target colder and colder audiences.
You reach people unfamiliar with the brand.
You expand into new markets.
You exhaust the conventional channels and start paying for the harder ones.

And on top of that, the marketplace for attention only gets more expensive over time.

So if the value of each customer isn't rising faster than the cost of acquiring them, you eventually hit the point where a new customer costs more than they're worth.

That's when a business quietly begins to go backwards.

And eventually, it collapses.

But I want to take this one step further.

Because I don't think lifetime value divided by acquisition cost is quite the right metric.

I think it has to be lifetime gross profit divided by acquisition cost.

Here's why that distinction matters enormously...

The easiest way to inflate lifetime value is to discount. Drop your prices, customers spend more, and the lifetime value number goes up. It looks like progress. But if those sales aren't profitable, you've changed nothing. You can still be paying more to acquire a customer than that customer is actually worth once you account for what it costs to serve them.

Revenue flatters. Profit tells the truth.

This is exactly why, when I talk about building a business, I focus on three things in a very specific order.

Retention first.
Referral second.
And only then, acquisition.

Because if your acquisition cost only ever moves in one direction then your lifetime gross profit per customer has to move in the same direction at a faster rate.

The only way to drive it there is to make sure every customer you acquire comes back again and again, and brings other people with them along the way.

That's what retention and referral actually do. They multiply the gross profit of every single customer you bring through the door, without adding a cent to what it cost to acquire them.

So watch that number closely.

Lifetime gross profit, relative to what it costs to acquire each customer.

If it's climbing, your foundation is getting stronger.

If it starts to fall, that's the first crack in your business model.

And cracks, if left alone, are what eventually bring the whole thing down.

If you know someone who would benefit from reading this, please forward it to them. It may change the trajectory of their life for the better, and the catalyst could be you.