The difference between fixed and marginal costs applies here. The costs you mention are essentially fixed costs. The marginal cost of a sale is then zero (igno

The difference between fixed and marginal costs applies here. The costs you mention are essentially fixed costs. The marginal cost of a sale is then zero (ignoring the cost of the item itself). With Stripe the marginal cost is 21c or 42%. You can increase sales ad infinitum and Stripe will still take 42%...