I think it's an alternative to second-hand and thrift shops, and the biggest advantage is that it is available even in areas without thrift shops. The second a

I think it's an alternative to second-hand and thrift shops, and the biggest advantage is that it is available even in areas without thrift shops. The second advantage is that you don't have to pay, so it is more likely that items will find a good home instead of being discarded. The third advantage is non-participation in the money system, if you're into that sort of thing, and also the elimination of overhead for store and inventory upkeep. One downside, of course, is that most people aren't willing to keep their "stock" around for too long, so there's limited inventory at any given time that you can browse.