Sale in 10 days — but the main risk isn't being late, it's entering at a loss

A seller with 300 SKUs received a notification about an upcoming sale. The marketplace requires submitting an application by the end of the week. The discount depth per the promotion terms is at least 20%. Three days remain to check all positions.

The question isn't whether they'll manage to submit the application. The question is which products to submit it for.

If they submit for all SKUs at once, some positions will enter the promotion with negative margin. If they check each one manually, there won't be enough time, and profitable products will be left out. Both scenarios lead to losses.

A sale isn't a yes-or-no decision for the entire assortment. It's an economic calculation for each position. Before submitting an application for a specific SKU, you need to go through four checks in order.

Check 1. Position economics

The first step is to recalculate the discounted price accounting for all confirmed expenses: purchase price, marketplace commission, logistics, storage, returns. If at least one value is unknown or outdated, it's better to postpone the decision on this position.

Example. A product sells for 2,000 rubles. Purchase price is 1,200, marketplace commission is 15%, logistics and storage is 150 rubles. Net margin before discount is 300 rubles.

Now the marketplace requires a 25% discount. Discounted price is 1,500 rubles. Commission is calculated from the new price: 225 rubles. Purchase price and logistics don't change. Total expenses are 1,575 rubles. Sale at a loss of 75 rubles.

This isn't an abstract loss of competitiveness. This is a concrete loss on every unit of product.

If there's no current data on commission, logistics, or purchase price for a position, it's too early to submit an application for it. First you need to establish the complete formula, then calculate the discount.

Check 2. Price floor

The second step is to determine the minimum price at which positive margin and required profitability are maintained. This is the lower boundary for participating in the promotion for a specific SKU, not a universal rule for the entire catalog.

Example calculation. Purchase price is 1,200, commission is 15%, logistics is 150, target profitability is 10% of sale price. Formula: price = (purchase price + logistics) / (1 - commission - profitability). Minimum price is 1,800 rubles.

If the marketplace requires a discount that pushes the price below 1,800 rubles, participation for this position isn't economically justified. You can lower the target profitability for the sake of sales volume in the promotion, but that's a conscious decision for a specific product, not automatic agreement to the marketplace's terms.

The price floor isn't a prohibition on lowering the price. It's the point below which the sale stops being profitable for the seller given the current expense structure.

Check 3. Specific promotion conditions

The third step is to check in the seller account the marketplace's requirements for participating in the specific sale: application deadline, minimum discount depth, requirements for matching the recommended retail price, product categories available for participation.

Promotion conditions vary. One sale may require a discount from current price, another from the maximum price over the last 30 days, a third from the stated RRP. If the seller recently raised the price before the promotion, the requirement for a discount from the maximum monthly price may make participation unprofitable even with acceptable current margin.

If promotion rules aren't found, are incomplete, or contradictory, participation for that SKU should be postponed until official terms are received from the marketplace. Submitting an application based on assumptions about requirements means accepting risk without being able to assess it.

Additionally, it's worth checking whether the marketplace has special requirements for product availability in the warehouse, delivery timelines, or quantity of available units. Participating in a promotion without sufficient stock can lead to penalties for underdelivery or loss of positions in search results due to product unavailability during peak demand.

Check 4. Competitor prices

The fourth step is to compare the planned discounted price with competitor prices on comparable offers. A competitor's price by itself doesn't prove that your own price should change. But it shows the price range in which the buyer will choose between offers during the promotion.

Example. A seller plans to participate in a sale with a price of 1,500 rubles after a 25% discount. A check shows that three main competitors for this position have already lowered their price to 1,400–1,450 rubles, product is in stock, listings are active.

This doesn't mean you need to automatically lower the price to 1,400 rubles. It means that at 1,500 rubles the product will be more expensive than most direct competitors at the moment of maximum traffic. The seller can make this decision consciously—if they have a better listing, more reviews, or higher buyout rate. But they should know about this difference before submitting the application, not discover it in the middle of the promotion.

Checking competitor prices isn't about finding the lowest price on the market. It's about assessing the context in which the product will sell during the sale.

Why manual calculation doesn't work here

The main problem isn't the complexity of the checks. Each of the four checks for an individual position takes 10–15 minutes: open the cost price spreadsheet, recalculate margin accounting for the new price, check promotion conditions in the marketplace account, find listings of three competitors, record their prices and availability.

The problem is scale. If the assortment has 100 SKUs, a complete check will take 20–25 hours of pure time. If there are 300 positions—more than a week of continuous work. The application submission deadline usually comes 3–5 days after the promotion announcement.

Under these conditions, the seller chooses between three strategies, and all three lead to losses.

The first strategy is to submit an application for all SKUs at once, without checking. Fast, but some positions will enter the promotion with negative margin. The seller learns about this after the fact, when prices are already applied and orders have started coming in.

The second strategy is to manually check the maximum number of positions in the remaining time. Realistically, that's 30–50 SKUs with a 3-day deadline. The rest either remain unchecked or are excluded from the promotion entirely. In both cases, the seller loses profitable products due to lack of time to check them.

The third strategy is to refuse participation in the promotion for all positions or for most of the assortment. Safe, but the seller misses out on additional traffic and sales for those SKUs where participation would have been economically justified.

None of the three strategies solves the original problem: submit an application only for those positions where the discount does not wipe out the margin and participation is economically viable.

Automation as an Admission Filter

Automating price monitoring and margin calculation does not replace the seller's decision. It changes the workflow: instead of manually checking hundreds of positions in limited time, the seller receives a ready-made list of SKUs filtered by four parameters.

The system tracks competitor prices on all marketplaces, regularly records changes, calculates margin taking into account current marketplace commissions and logistics for each SKU, and compares the planned discounted price with the lower threshold of profitability.

The output is a table with three groups of positions: green zone (margin is preserved, price is competitive, participation is justified), yellow zone (margin is positive but below target—requires a decision), red zone (participation leads to a loss).

The seller sees the full picture before the application deadline and makes a decision for each group: send green to the promotion, check yellow manually, exclude red.

This is not automatic price changes. This is automatic condition checking before a manual decision.

When Participating in a Promotion Costs More Than Declining

A sale is not a universal opportunity for sales growth. It is a tool with clear economic boundaries of application. Participation is profitable when the discounted price preserves an acceptable margin, the product is competitive in its category, and there are enough units in stock to cover possible demand growth.

Participation costs more than declining when the required discount depth pushes the price below cost price including all expenses, the seller did not check current competitor prices and discovered the difference in the middle of the promotion, or the decision for hundreds of SKUs was made a day before the deadline without individual recalculation.

The main risk is not that the seller will miss the application deadline. The main risk is that they will submit it for products where participation is inherently unprofitable, and learn about it only after the promotion has started and prices have already been applied.

Before submitting an application for a sale, it's worth asking one question for each SKU: if I sell this product at the discounted price taking into account all expenses—will I have a margin that I consider acceptable? If the answer is unknown—participation for this position is better postponed until it's checked.