This would be a website similar in structure to Etsy or Ebay, but with a charitable purpose.
The sellers could choose a % of the price of their items to go to a charity they support (sellers can choose anywhere between 50 and 100%). They could sell items they no longer need or arts&crafts type of objects. They could post these free of charge, and a small fee would apply to every transaction.
The buyers would pay as they would on Amazon, Ebay etc, but their money would go to a charity and/or seller.
Why this would work:
- people have a lot of things they would like to get rid of, and donating makes people feel better;
- people tend to buy things more if they know their money is going to charity (from experience working in a physical charity shop).