Mountain Stone.

The Financial Architecture.

The Playbook / System 02 · Structure

The unit economics underneath every acquisition decision.

System
02/10
Class
Structure
Governs
Every dollar of spend
Enforced
Daily floor
The Playbook
The wrong number

Most brands have a target CAC. Fewer can tell you exactly where it came from.

Often it starts as a benchmark or a number that felt reasonable at the time. Once it becomes the target, spend gets managed around it even when the economics underneath the business have changed.

The cost of a blended number

A single CAC target can hide very different economics across the product line. One product may support much more spend than another, but the blended number treats them the same. That can leave good opportunities underfunded while weaker ones keep absorbing budget.

Timing matters too. Month-end reporting can explain what happened, but it arrives too late to affect today’s spend. Financial Architecture keeps the economics close enough to the work that decisions can change while there is still time to act.

The principle

Profitable growth is solved before the money is spent.

Before we scale a product, we know what the business can afford to spend acquiring the next customer.

The system

Financial Architecture turns the brand’s unit economics into rules the team can actually operate from.

The foundation is the Contribution Margin Stack. It gives us a clear view of what each product earns before acquisition, then tells us what the business can afford to spend to sell another one.

CM1 starts with revenue after landed product cost. CM2 accounts for the costs attached to fulfilling the order, and CM3 brings acquisition into the picture. CM2 sets the ceiling for what we can afford to spend. CM3 tells us what is left when we do.

From there, every product gets its own CAC ceiling. A $40 product with $20 of CM2 can support a very different acquisition cost than a $30 product with $8. A blended target hides that difference and can leave one product underfunded while another absorbs spend it cannot support.

Break-even ROAS comes from the same economics. If CM2 is 48%, break-even ROAS is 2.08. That number stays close to the work because it needs to influence decisions while spend is happening, not at the end of the month.

The numbers are already there

Most brands already have the information Financial Architecture needs. The problem is that it lives in different places and rarely gets brought together at the product level.

Financial Architecture connects those numbers and turns them into something the team can use every day. Once the economics are visible by product, the limits of a single blended target become obvious.

In operation

One set of books.
One shared math.

The same economics that run acquisition also give the rest of the business a clear view of what each product can support.

The contribution margin stackPer product · Recomputed monthly
REVENUE
What the product sells for
CM1
Minus landed cost of goods
CM2
Minus shipping, fees, returns · The floor for paid
CM3
Minus ad spend · Where profit lives
The campaign surface · Ceilings

Every acquisition decision is held against the economics of the product behind it. Instead of one blended target, each product gets the ceiling its margins can actually support.

That gives the team a much cleaner answer to when spend should move.

The team surface · One truth

Finance and acquisition work from the same economics, while product can see where there is enough margin to support more growth. The numbers become useful beyond the ad account.

The business starts making decisions from the same numbers.

The test

Three questions.

Answer them without opening a spreadsheet.

01What is the CAC ceiling on your hero product?
02What is its break-even ROAS?
03The last time the team scaled or killed a campaign, was the decision based on that product’s economics or a blended target?

If any answer is "we would have to check" or "we use blended," the Architecture is not operational yet.

What profitable growth actually is

When the Architecture is working, spend can move with the economics of the business. Products with room to scale get more behind them, while the ones without it get pulled back before the problem shows up at month end.

The Financial Architecture
Profitable growth is a math problem, solved before the money is spent.