This case study evaluates the economic, social, and environmental effects of three online platforms. Craigslist provides an online market for local secondhand goods such as vehicles, furniture, appliances, and electronics. Couchsurfing matches travelers with hosts around the world who welcome guests into their homes. NeighborGoods helps people borrow and lend household goods free of charge. Together these case studies provide an overview of the role of online platforms as future economy initiatives.