To profit on Black Friday, set the maximum discount product by product based on contribution margin, make sure inventory and operations can handle the peak, warm up audiences weeks in advance, test the checkout and plan the post-sale. Selling a lot with a discount above the limit means paying to sell.
Black Friday is the date that concentrates the most e-commerce sales, and also the one that hides the most losses. Revenue goes up, the team celebrates and, weeks later, the books show the numbers didn't add up. The problem is rarely selling too little: it is selling a lot with the wrong discount.
1. Start with finance: what is your maximum discount?
Before choosing the offer, calculate each product's contribution margin:
- Selling price
- minus product cost
- minus taxes and platform and payment fees
- minus subsidized shipping
- minus the expected customer acquisition cost (CAC) on the date
What is left is the margin available for discounts. If the discount goes beyond that limit, every order becomes a loss, and the more you sell, the more you lose.
To simulate scenarios with your own numbers, use the f.up Black Friday Margin Calculator (in Portuguese). It shows the recommended maximum discount, the minimum price and the campaign's break-even point.
2. Inventory and operations for the peak
- Review the ABC curve and secure stock of your best sellers.
- Align capacity with logistics and the distribution center.
- Test the ERP, the platform integration and invoicing at volume.
- Set realistic delivery times and communicate them clearly.
3. Offer: discounts are not the only lever
Smart offers protect margin:
- Kits and bundles that raise average order value.
- Gift or free shipping above a threshold instead of a flat discount.
- Tiered discounts by quantity.
- Exclusive offers for your customer base, which cost less in media.
4. Acquisition: warm up before, convert on the date
During Black Friday week, media auctions get more expensive. So:
- Start warming up 3 to 4 weeks ahead, with content and lead capture.
- Build remarketing and customer lists to activate on the date.
- Review the product feed and prepare creative in advance.
- Set ROAS targets per category based on real margin. See how in our guide to paid media for e-commerce.
5. Checkout and site able to handle the traffic
- Load-test store speed and stability.
- Review the mobile checkout: shipping, coupons and payment without friction.
- Make the return policy and delivery time visible.
- Turn on cart recovery via email and WhatsApp.
6. Retention: Black Friday continues after the date
New Black Friday customers are the campaign's most valuable asset. Plan:
- Welcome and post-purchase flows.
- A second-purchase offer in the following weeks.
- Fast support for returns and questions, which drives repeat purchase.
f.up's complete checklist
We organized all these points in a practical guide: the Black Friday Checklist: opportunity or trap? (in Portuguese), with 25 checkpoints across 5 pillars (finance, operations, offer, acquisition and retention), a final 8-item review and 3 actions for the 7 days after the date. See also the other f.up resources.
Need help planning your Black Friday? Talk to f.up.
Frequently asked questions
How much discount should I give on Black Friday?
The maximum discount depends on each product's contribution margin, after cost, taxes, fees, subsidized shipping and acquisition cost. A margin calculator helps you find the limit before announcing the offer.
When should I start preparing for Black Friday?
Ideally, planning starts 60 to 90 days ahead. Warm-up media and lead capture usually begin 3 to 4 weeks before the date.
Is Black Friday worth it with low margins?
Only if the date serves a clear goal, such as acquiring new customers with good repeat-purchase potential. Otherwise, selective offers on high-margin products or bundles are a better choice.