Why a platform commission hurts
When a platform sits inside the sale, it takes a percentage of every transaction, sometimes on top of a subscription. On a 20 EUR product sold a hundred times, a 5 percent commission is 100 EUR gone, every month. Over a year that is real money leaving your account without a single itemized invoice you can look at.
The alternative is simple: sell from a page you control, using your own PayPal or Stripe account. The buyer pays, the money arrives with you, and no intermediary platform takes a share of the amount.

