Ask HN: Sideprojects/passive income businesses with little or no own coding?

Whenever sideprojects or ways to gain passive income are discussed here, the conversation focuses on programming projects that can be run on the side. Of course, this is very much connected to the nature of the side.

However, I'd like to hear from people who do/did sideprojects that involved little programming from their side and that, maybe, even provided them with a passive income. For me it's a bit difficult to imagine such projects and I think it would be a novel topic to talk about.