Amazon economics
Marketplace referral fees and optional fulfillment or advertising costs can be important parts of the model.
Shopify economics
A direct store can involve payment processing, subscription allocation, apps, fulfillment, customer acquisition and other operating costs.
Compare one SKU fairly
Keep price, COGS, shipping, fulfillment and return assumptions consistent, then change only the channel-specific economics. This is the logic behind our marketplace comparison engine.
Use the numbers
Educational guidance is most useful when paired with your own SKU economics. Run the same assumptions through the calculator, then compare marketplaces if channel selection is part of the decision.