You already have an audience
A club, a school, a community, a mailing list. You bring the traffic, so you may as well keep the margin that comes with it.
Both sell print-on-demand merch. What they don't share is who owns the customer, the brand and the margin. Here is the difference, plainly.
A marketplace is a shop selling thousands of people's designs to strangers who happened to pass by. You upload a graphic, it handles the rest and pays you a commission. An official store is your shop, in your name, where your community comes because it is yours. You set the price, you keep the difference, and you know who bought.
| On a marketplace | On your official store | |
|---|---|---|
| The customer | Belongs to the platform. You don't know who they are. | Yours. You have their email, their history, their size. |
| The brand | Theirs. Your name is a line in a catalogue. | Yours. The address, the colours and the logo are yours. |
| The price | They set it, often with discounts you absorb. | You set it. It doesn't move without you. |
| The margin | A commission, typically 10 to 20% of the sale price. | The difference between your cost and your price. You choose it. |
| Competition | Your pieces sit next to everyone else's. | None. Your store shows only you. |
| Traffic | They bring some, and that is their real service. | Yours: your members, your followers, your list. |
If you don't have a community yet, a marketplace brings you buyers you would not have had. That is its trade, and it does it well. An illustrator starting out will sell more there than on a store nobody knows. The question isn't which is better, but whether people already follow you. If they do, sending them elsewhere is expensive: you pay a commission on traffic you brought yourself.
A club, a school, a community, a mailing list. You bring the traffic, so you may as well keep the margin that comes with it.
An organisation's merch is worth something because it is official. A line in someone else's catalogue does not say the same thing as an address in your name.
To follow up, to plan the next run, to understand. On a marketplace that information never reaches you.
A back-to-school drop, an anniversary piece, a pre-order with a minimum. A marketplace sells continuously, not in campaigns.
If people already follow you, open the store that carries your name. You set the prices, you keep the margin, and you know who buys.