Your customers have started asking ChatGPT what to buy. “A carry-on backpack that fits under the seat,” “a quiet fan for a small bedroom,” and the assistant may answer with real products: images, prices, and a link to a store. Accurate product data helps ChatGPT understand what you sell, and a product feed is the structured way to supply it. Submitting a feed doesn’t guarantee that your products appear in any given answer, but without one, ChatGPT has nothing reliable to work with.

Expanding to a new marketplace shouldn’t cost you hours of listing work. NordicSneakers, a fast-growing Danish sneaker marketplace, lets you list with just a SKU and a size, then builds and markets the product pages for you. Here’s how selling on NordicSneakers works, who it suits, and how to run it alongside your other sales channels without overselling.

To sell on OnBuy, you register as a seller, list your products in the format OnBuy requires, and keep your stock and orders in sync. The quickest way to do all three is to connect your existing store to OnBuy with Koongo, which automates the data work so you can list in an afternoon rather than a month.

But before the how, the why. OnBuy has a few things going for it that set it apart from the marketplaces most sellers start with. Here’s what OnBuy is, why sellers are moving to it, the one real challenge in getting listed, and exactly how Koongo handles that challenge.

This offer is an early-bird deal: pay for one month of your seller subscription by 31 July 2026, and your next 12 months of subscription are free, so you get 13 months of selling for the price of one. Because OnBuy, easyShop, and Comet all run on the same OnCommerce account, that single subscription covers all three marketplaces as they launch. Standard selling fees on your actual sales still apply, so it’s the subscription cost that’s waived, not selling on the platform entirely.

A new marketplace, easyShop, is launching for peak season 2026, and if you already sell on OnBuy you’re closer to being on it than you might think. The reason is OnCommerce: the platform that connects OnBuy, easyShop, and the returning Comet brand, letting sellers reach all three through a single account and a single product catalogue.

But what exactly is OnCommerce, how does the one-account model work, and what does each marketplace offer a seller? This guide breaks it down in plain terms: what OnCommerce is, the three marketplaces it powers, how listings, stock, and payments stay in sync across them.