A seller joins because the commission looks reasonable. She prices her products on that basis and expects a particular margin.
Payment processing is deducted separately. Commission is charged on the shipping she collects. A promoted listing fee applies to some sales. Her actual margin is materially lower than she calculated, and she discovers it across three months of statements.
What a sale actually costs a seller
Four or five components. The commission, the payment processing charge, any listing or subscription fee, any promotional charge, and any fulfilment charge where the marketplace handles despatch.
Component 1: the commission
A percentage, frequently varying by category. The percentage is the number sellers compare and it is rarely the whole story.
Component 2: whether commission applies to shipping
If a seller collects shipping and pays commission on it, the effective rate on the item is higher than advertised. This single detail changes margin calculations significantly.
Component 3: payment processing
A percentage plus a fixed amount per transaction, charged separately from commission. The fixed component hurts low value items disproportionately.
Component 4: listing or subscription fees
Monthly, per listing, or free with limits. Fixed costs matter enormously to low volume sellers and barely at all to high volume ones.
Component 5: promotion and fulfilment
Optional and frequently not experienced as optional once competitors use them. They should be presented as a cost with a measurable return rather than a necessity.
A worked example
An item sells for forty pounds with five pounds shipping collected. Commission at twelve per cent on the full forty five is five pounds forty. Payment processing at two per cent plus twenty pence is a further pound ten. The seller receives thirty eight pounds fifty against a forty five pound transaction.
What that means against the headline rate
The advertised commission was twelve per cent of the item price, which would be four pounds eighty. The actual deduction is six pounds fifty, an effective rate of over fourteen per cent once shipping and processing are included.
What a refund does to the arithmetic
If commission is retained on a refunded order, a seller with a ten per cent return rate is paying fees on sales they never made. This is the detail most worth publishing plainly.
Publish a calculator rather than a table
Sellers want to know what they receive on their own item at their own price. A worked figure converts far better than a fee schedule, which is the ground in commission and fee questions sellers ask before joining.
Explain when the money actually arrives
Payout schedules, holds on new sellers and reserves, which is set out in marketplace payment and payout questions answered.
Explain the fee changes policy
How much notice is given and whether categories can be reclassified. Sellers building a business on a rate need to know how stable it is.
Remember the buyer side has fee questions too
Service charges and delivery costs affect conversion, which is covered in what buyers ask about fees and why it matters.
Answer the fee question with real numbers
An assistant that takes a seller's price, category and shipping arrangement and shows exactly what lands in their account attracts sellers who price properly and stay, rather than sellers who join on a headline and leave on a statement, handled with the care in how to handle sensitive questions in your chatbot where account data is involved. See pricing, run the numbers on the chatbot ROI calculator, and the sector view sits under ecommerce.