Sell on the marketplaces from one catalogue.

Amazon listings are matched to Amazon’s catalogue by barcode or created with the attributes its category requires, and orders arrive through the Selling Partner API. Fulfilment is either your own (merchant fulfilled) or Amazon’s (FBA), and the integration has to know which, because FBA stock sits in Amazon’s warehouses and not yours.

For Shopify, Shopify’s own Marketplace Connect app covers many sellers. On Magento the common route is an extension such as M2E Pro. Custom work comes in with variations that don’t map to Amazon’s, bundles, several sellers’ accounts or regions, and orders that must reach an ERP or OMS rather than the store.

eBay listings are built from your products with item specifics per category, and orders come back through eBay’s APIs. The same connectors that handle Amazon usually handle eBay. Custom work is typically in item specifics, multi-variation listings and business policies for postage and returns.

TikTok Shop lets people buy inside TikTok, from videos, live streams and the shop tab. For Shopify stores TikTok’s own app syncs products and orders. Outside Shopify, or where products need restructuring for TikTok’s categories and rules, the connection is built on TikTok Shop’s partner API.

Google Shopping is fed from Google Merchant Center, which reads your products from a feed or its API. Most problems are data problems: disapproved products, missing identifiers such as GTINs, prices or stock that don’t match the landing page, and shipping settings that disagree with the checkout.

A clean feed built from the store, or from the PIM, with the fields Google needs, is often worth more than any bidding change. Free product listings and ads both depend on it.

Most other marketplaces work the same way: a listing format, a category tree and an orders API or file. Once one marketplace is connected properly, through an OMS or a multichannel tool, adding the next is mostly mapping.