Marine Layer will sell you an empty bag for $20.
You fill it with old clothes. Any brand, almost any condition. You mail it back with a prepaid label.
They give you $40 in store credit.
Read that again. You pay twenty dollars for a bag, send them your garbage, and receive forty dollars.
On the surface that is a company paying customers to take away trash. In practice it is one of the more interesting pieces of retail arithmetic running right now, and the reason it works has almost nothing to do with recycling.