Fee Updates
How SellerEconomics records marketplace fee sources, review dates and known caveats.
Source-first fee data
Fee values should come from official marketplace sources wherever possible.
Every production fee value should have a source URL, effective date where available and last reviewed date.
Known caveats
Amazon and eBay fees often vary by category, price band and fulfilment details. Those calculators should show scenario caveats until full category selection is available.
Shopify and payment fees can vary by plan, card type, country, payment provider and subscription assumptions.
Review rhythm
Review fee sources before production launch, after public marketplace fee announcements and during scheduled maintenance.
If a fee cannot be verified, mark it as needing verification rather than silently blending it into a calculator.