I wish someone had clued me in about these earlier! I joined one a couple of weeks ago for my city that has kind of a more upscale focus and it has been SO EASY to unload stuff compared to Craigslist. I just sold our couch in like 15 minutes! And nice kids' stuff goes reaaaally fast, too. I keep trying to snag a cheap double stroller and someone always snaps it up like 30 seconds before me, ha.