How to prepare El Buen Fin 2026 with the data you already have (and measure it like never before)
By Enrique Miralda · October 26, 2026 · 5 min read
El Buen Fin is won or lost before it starts. From 13 to 17 November, almost every retailer in Mexico will do the same thing: a general discount and a mass send to the whole database. The ones who do best are not the ones who discount most, but the ones who know who to talk to with each discount.
Three weeks to go. It is no longer the time to change tools in order to activate campaigns. It is the time for two things: doing well what you can do with what you have, and measuring this Buen Fin like never before, because that you can still make.
Before the detail, watch in three and a half minutes what the whole job looks like when customer data is unified and connected to your channels: connect, segment, activate and measure. Keep the last step in mind, because it is the one you can have running on this Buen Fin. The video is in Spanish.
Del dato al valor: prepara tu Buen Fin con FLYDE · 3:30 · in Spanish
This year: four lists you can pull with what you have
You do not need a platform for this. You need someone to spend two or three afternoons cross-referencing the exports from your loyalty programme, your ecommerce and the store receipts that carry an email or phone number. That gives you four lists that change the picture of El Buen Fin.
| List | Who they are | What to tell them | Channel |
|---|---|---|---|
| High-value dormant customers | Bought 2+ times in 2024-2025, above-average ticket, no purchase in 6-9 months | Early access or an exclusive benefit, not the general discount | Email + WhatsApp, two weeks ahead |
| Buen Fin 2025 buyers who never came back | Bought in November 2025 and nothing since | A reminder of what they bought and an offer in the adjacent category | Email + remarketing |
| Browsed or abandoned a cart in October | Viewed or added products without buying in the last 4 weeks | A heads-up that the product is going on promotion | Email + push + remarketing |
| Exclusions | Paid full price in the last 2-4 weeks; recent return; asked not to be contacted | Nothing: they do not receive the campaign | Suppression list on every channel |
The fourth list is the most profitable and the most forgotten. Sending a 30% discount to someone who paid full price ten days ago generates returns, complaints and lost margin. Excluding them costs nothing. And it is impossible without cross-referencing store and online purchases, which is exactly what is usually missing.
The thresholds (6-9 months, 2 purchases) are starting points. The right cut-off depends on the purchase cycle of each category; if you have the history to hand, the data itself tells you where it is.
Hold out a control group, even by hand
During El Buen Fin everyone sells more, so total sales tell you nothing about your campaigns. There is one decision that can only be made before launch, and that no tool can reconstruct afterwards: leaving 5-10% of each list out of the campaign. That is your control group.
With it, in December you can answer the only question that matters: how much of the sales did the campaign cause and how much would have happened anyway. Without it, the report will say everything worked. Two more rules: measure by list, not by send, and do not change a list’s definition mid-season, because it destroys the comparison.
Measure this Buen Fin like never before
Here is what you can change this year. Activating segmented campaigns requires unified data before launch. Measuring them does not: the Buen Fin data will end up in your ecommerce, your loyalty programme, your receipts and your ad platforms regardless. If you connect those sources now, in the two weeks the video shows, the whole of November lands in a single customer record. And in December you see, for the first time, things you cannot see today with the sources apart:
- Which list responded and which did not, compared with its control group.
- How much discount went to customers who would have bought at full price, and how much margin it cost.
- Which channel really converted, by segment rather than by campaign.
- Who bought for the first time during El Buen Fin and who needs winning back before Reyes.
That is the analysis usually done in a spreadsheet in January, with partial data, when it no longer helps. Done on unified data, it is the starting point for everything that comes next.
And from there, activate
With El Buen Fin measured, next season’s lists are not built from scratch: they are built from what you have just learned. The video’s timeline is realistic: sources connected in two weeks, first segmented campaigns in month two, return measured in month three. Starting now, you reach the January sales with lists recalculating themselves, Hot Sale with exclusions up to date and Buen Fin 2027 with a year of history working for you.
And every step is faster with Brain: the list of “active customers who only buy with a 30% discount or more” is requested in natural language, and the offer, the channel and the timing for each segment are proposed by Brain from historical behaviour.
The segments that really move margin in retail
The four lists and the control group are the minimum for this Buen Fin. If you want to go further, we have published a guide to the eight highest-impact segmentation models in retail, from RFM to predictive, with the signal, the KPI and the common mistake of each. It is the Mexico 2026 edition and uses Hot Sale and El Buen Fin as its margin laboratory. One of the eight models, price sensitivity, is exactly the one you see in the video.
And if you want this Buen Fin to land whole in your customer data, let’s talk before the 13th. You bring the data. FLYDE finds the way.