An Old Idea or a Bad Idea?

I am working off not enough sleep, so this may already exist or be a bad idea, but this thread got me thinking and so I posted this idea on Mastodon:

What if there was an interoperability commerce-focused protocol (built like ActivityPub does for content) where sellers could connect their single listing/post/etc. to many websites without having to manage the item individually on each website and the websites made money by commissions through a sort of affiliate program if the purchase was made through them?

I'm not a tech/programmer person, I'm more of a systems person, so I'm a bit out of my element.