In Brazil we have this http://www.cataki.org/ (pt-br) an app that connects waste pickers to people who want to dispose reusable or recyclable materials.

According to this site 800,000 waste pickers in the country and 300 registered on the service.

I don't agree with all of David Siegel's views, but I first came across the concept of having a set of things you own always passively for sale (what he calls 'passive commerce') in his vision for pillar: "https://youtu.be/2VdICMlvo68?t=230" (from https://medium.com/@pullnews/announcing-the-pillar-project-1... )

As someone who wants a more waste-free society and already keeps a running list of craigslist items for sale, ebay/cl watchlists, etc. I'd be open to innovation in this space.