Moving a product from FBO to FBS may reduce one cost and increase another. Comparing a single commission line does not tell you which model leaves more profit. Build two versions for the same SKU, period and definition of a sale.
1. Fix the comparison unit
Record the marketplace, SKU or variant, period and unit: order, fulfilled sale or fulfilled sale after returns. These are different events. If the selling price or fulfilment rate changes between scenarios, state that as an assumption rather than an inherent property of FBO or FBS.
2. Apply a complete cost list to both models
Include revenue after discounts, marketplace fees, outbound and return logistics, storage or handling, your own packing and labour, advertising, purchase cost and other allocated expenses. A cost may attach to an order, a fulfilled sale or a whole period. Document the allocation base. Missing is not zero.
Suppose a unit produces ₽1,000 in revenue and has ₽720 in confirmed variable costs: contribution is ₽280. If in-house FBS handling has not been measured, ₽280 is not proven FBS profit. With an illustrative handling range of ₽40–90, the result before other gaps is ₽190–240. These are teaching numbers, not marketplace rates or customer results.
3. Reconcile timing and sources
Advertising charges, logistics and returns can arrive after the sale. Keep each export date and the rule for assigning late costs to a SKU. Check a sample of orders against source reports and internal records. Our missing-cost checklist shows how to mark each component complete, partial or absent.
4. Vary one assumption at a time
Find the return rate or handling cost at which the preferred model changes. Assess working capital and warehouse workload separately. When history is thin, call the calculation a scenario, then run a limited test and reconcile actual charges before moving a large assortment.
ProfitVena helps inspect available marketplace data, configured costs and supported imports. Completeness depends on connected sources, SKU mapping and accounting rules; the team still verifies source figures. Technical updates are available at profitvena.ru. ProfitVena is part of the Wicsora ecosystem. Русская версия.
