Marketplace fees: the cost line most sellers underestimate
Sellers quote themselves a single headline percentage. Actual fee load is a stack of category commission, processing, per-order fixed charges and optional promotion — routinely half again the number people carry in their heads.
- 5
- 13–19%
- +3–6pt
commission, processing, fixed, promotion, shipping
of gross sale on consumer electronics
gap between quoted and effective rate
What the stack contains
MarginMap models each layer independently so you can see which one is eating the deal.
- Category commission
- Varies by marketplace and category, sometimes tiered by sale price.
- Payment processing
- A percentage plus a fixed per-order charge, which dominates on low-value items.
- Fixed order fees
- Flat insertion or transaction charges applied regardless of price.
- Promoted listings
- Optional ad rate applied to the final sale price; often the difference between selling this month and next.
- Shipping subsidy
- Free-shipping offers are a seller cost. Modelled as a line, not ignored.
Why fixed fees decide low-value flips
A flat 30-cent-plus-percentage processing charge is a rounding error on a 900 dollar sale and a material tax on a 25 dollar one. The evaluator shows effective total fee percentage per deal, which is what makes small-item arbitrage visibly unattractive well before you have bought forty of them.
Store subscriptions and negotiated rates
Volume sellers rarely pay list rates. Every default in the fee schedule is overridable, and overrides persist per marketplace in your workspace so the pipeline and evaluator both reflect your actual economics rather than the public rate card.
Frequently asked
Keep reading
Run one product through it
Open the workspace, search in plain language, and open the evidence drawer on the first number you doubt.