Amazon Black Friday Deals UK: Why Protecting Your Margins Matters More Than Increasing Sales

Black Friday is one of the biggest promotional opportunities for Amazon UK sellers.

But there's something I always encourage sellers to consider before committing to discounts:

Are you increasing profit, or simply increasing revenue?

A successful Black Friday campaign shouldn't be judged purely by sales volume.

It should be judged by what remains after discounts, Amazon fees, advertising and other costs.

1. Understand the Real Cost of Your Black Friday Discount

A 20% discount doesn't necessarily mean your profit falls by only 20%.

Consider this simplified example, excluding VAT and assuming the same per-unit fees:

Your selling price has fallen by 20%, but your contribution per unit has fallen by 50%.

And that's before additional advertising costs.

Calculate promotional profitability before committing to a deal.

In practice, some fees change with selling price, and VAT treatment must be considered. Use your actual SKU-level figures.

2. Don't Forget the Cost of Amazon Promotions

Depending on the promotion type and eligibility, sellers may face additional costs or conditions.

These can include:

• Deal participation fees.
• Coupon or voucher fees.
• Minimum discount requirements.
• Price-history eligibility rules.
• Additional advertising spend.

Always check the current fees, eligibility and promotional conditions inside Seller Central.

A promotion that looks attractive from a sales perspective may be less appealing once all costs are included.

3. Recalculate Your Break-Even ACOS

One of the most important PPC calculations during Black Friday is your break-even ACOS.

Break-even ACOS = Contribution margin before advertising × 100

Using the example above:

• Normal break-even ACOS: 40%
• Discounted break-even ACOS: 25%

A campaign generating 30% ACOS could be profitable before the discount but unprofitable during the promotion.

This is why maintaining the same PPC strategy throughout Black Friday can be risky.

Recalculate break-even ACOS for every promoted product using its discounted selling price.

4. Don't Chase Revenue at Any Cost

During Black Friday, sellers often become focused on:

• Increasing sales volume.
• Winning more advertising placements.
• Raising PPC budgets.
• Matching competitor discounts.

But these actions don't always improve profitability.

Sometimes a smaller discount, supported by efficient advertising, generates better total profit than an aggressive promotion.

For example, selling 500 units at £8 contribution each produces £4,000 before advertising.

Selling 800 units at £4 contribution each produces only £3,200.

More sales. Less contribution.

That is why volume alone should never determine whether a Black Friday campaign has succeeded.

5. Know When Not to Run a Deal

Not every product needs a Black Friday promotion.

Consider avoiding or reducing discounts when:

• Margins are already tight.
• Inventory is limited.
• Organic sales are performing strongly.
• PPC costs are unusually high.
• The product has strong year-round demand.

A promotion should have a clear commercial objective, such as acquiring new customers, improving stock turnover or generating profitable incremental sales.

Final Thoughts

Black Friday can be a fantastic opportunity for Amazon sellers, but it can also expose weaknesses in pricing and advertising strategy.

Before launching any promotion, understand:

Selling price → Contribution margin → PPC cost → Net profitability

The goal should never be simply to sell more products.

It should be to make more money from the business.

Need Help Improving Amazon PPC Profitability?

At Denver James Ltd, I work with UK Amazon sellers to improve advertising efficiency, manage TACoS and build more profitable growth strategies.

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