This one sort of skirts on the edge of interest for Web professionals, but with some creative thinking, I'm sure you can make it work (wink, wink).
Facebook relaunched Facebook Marketplace (now powered by Oodle) to let its users create, share and respond to classifieds listings.
Late last year, Facebook turned to Oodle for its expertise in online classifieds, and Oodle has built an entirely new version of the Marketplace app focused on giving people a place to buy, sell or give things away to the people they know. FB users can sell pretty much anything for a profit, sell it for a cause (see below), give it away or ask for things they need. I hope you can see the value in using the app - even it's just for fun. Give away your most recent white paper, sell your product and give the proceeds away to a charity, etc. The opportunity is truly unlimited.
Facebook is also introducing new features including Sell for a Cause, which allows FB users to donate the profits of the items sold to over a million participating charities including UNICEF, the Sierra Club and local organizations like the Boys and Girls Club of San Francisco.