Italo Barros
Planning Black Friday means answering eleven questions — and none of them is the discount
The calendar says when. The maths says how much. The eleven questions that settle the target, the customer base, acquisition and profit before November — with the full workings of an R$ 300 thousand operation.
What you will learn here
- Four questions about the target and the base tell you how many orders your existing customers already deliver on their own.
- The new-customer gap is what defines how much you need to capture and how much it will cost.
- Four extra points of repeat purchase rate were worth R$ 12.500 more in results — and R$ 12.500 less in media spend.
A question we put to a room of 80 e-commerce operations adding up to R$ 5 million a month: how did you set your last Black Friday?
There were four answers:
- I looked at what I did last year
- I looked at what the competition was doing
- I picked a number that looked about right
- I decided on the discount and saw what happened
Not one of them starts with the maths. And that is exactly why, come January, the margin has vanished.
You don't plan a day. You plan a quarter
October is planning. From 2 to 11 November is early Black Friday — the window in which you sell before the media auction gets expensive and before the whole market starts talking at once. December is shipping and delivery times.
The calendar says when. The maths says how much. And the maths means answering eleven questions, in four blocks.
The eleven questions
1 · The target
- How much do I want — revenue
- How much is each order worth — average order value
- How many orders do I need — orders
2 · The base
- How big is my base — active customers
- How much does it deliver on its own — repeat purchase rate
- What is the gap — new-customer orders
3 · Acquisition
- How well does a new lead convert — conversion rate
- How many leads do I need — lead volume
- How many do I already have — lead base
- At what cost — CPL
- How much do I invest — budget by stage
4 · Profit
- What is left — gross margin
The full workings
It is worth more to see the maths running than to describe the method. The numbers below come from a mid-sized operation.
The target
| Question | Indicator | Value |
|---|---|---|
| How much do I want | Revenue | R$300.000,00 |
| How much is each order worth | Average order value | R$250,00 |
| How many orders do I need | Orders | 1.200 |
The base
Before buying a single click, look at what the house already delivers.
| Question | Indicator | Value |
|---|---|---|
| Active base | Customers | 5.000 |
| How much it delivers on its own | Repeat purchase rate 12% | 600 orders |
| What is the gap | New-customer orders | 600 orders |
Half the target is already in the house. It is the other half that has to be bought — and now you can tell what it costs.
Acquisition
| Question | Indicator | Value |
|---|---|---|
| New-lead conversion | Rate | 4% |
| How many leads do I need | Lead volume | 15.000 |
| How many do I already have | Lead base | 8.000 |
| How many do I need to capture | Capture gap | 7.000 |
| At what cost | CPL | R$2,50 |
| Lead capture in October | Budget | R$17.500,00 |
| Conversion in November | Budget | R$15.000,00 |
| Total investment | Budget | R$32.500,00 |
Profit
A gross margin of 40% on an average order value of R$250,00 gives R$100,00 per order. Across 1.200 orders, that is R$120.000,00 of gross margin. Less the R$32.500,00 of media spend, R$87.500,00 is left.
| Source | Orders | Gross margin | Media cost | Left over |
|---|---|---|---|---|
| Base | 600 | R$60.000,00 | — | R$60.000,00 |
| New | 600 | R$60.000,00 | R$32.500,00 | R$27.500,00 |
Look at the last column. The same number of orders, coming from different places, leaves more than twice as much money when it comes from the base. Gross margin here does not include fixed costs, tax, shipping and fees — in your own real workings, include them.
The five levers
If your maths didn't add up, it is one of these five you are going to move:
| Lever | How it moves | When |
|---|---|---|
| Repeat purchase rate | CRM, active base, segmentation, VIP | Before |
| Conversion rate | Page, checkout, social proof, payment | Before |
| CPL | Channel, creative and capture offer | Before |
| Average order value | Kit, bundle, tiered shipping, upsell | Before |
| Discount | Only by discounting more | During |
Four of them move beforehand. Only one moves during — and that is precisely the one most people use, because it is the only one still available when nobody planned.
Four points of repeat purchase rate
Go back to the same maths and change a single variable: the repeat purchase rate from 12% to 16%.
| Repeat rate 12% | Repeat rate 16% | |
|---|---|---|
| Base delivers | 600 | 800 |
| Gap | 600 | 400 |
| Leads to capture | 7.000 | 2.000 |
| Investment | R$32.500,00 | R$20.000,00 |
| Gross result | R$87.500,00 | R$100.000,00 |
Four percentage points were worth R$12.500,00 more in results and R$12.500,00 less in media spend. Same target, same average order value, same discount — and R$25.000,00 of difference in the bank.
That is why the maths comes before the calendar: it shows you where the effort pays off. And it is almost never the discount.
With the maths settled, the next step is execution: the offers, the early launch and the VIP group are in Black Friday in practice, and what to do after the day itself is in Your Black Friday closes in March. Of the five levers, the two that change the result most are the repeat purchase rate, which is CRM work, and the CPL, which is paid media work — and both of them move before November, not during it.
This is the opening session of Black Experience 2026, held on 26 September in Campinas, with 80 e-commerce operations in the room.
“The calendar says when. The maths says how much.”
