I've been meaning to mention this app called Yerdle (they have a website, but you need the mobile app to actually post and buy).
I've been using it since the summer of 2014 and it's been such an awesome way to get rid of stuff in my house and my studio - including fabric, ribbon, product I tried but didn't sell. I've also gotten rid of a lot of weird things like used make up, a bra and lots of kid toys. In return I was given credits and was able to use those credits to "win" a lot of awesome things like shoes for my daughter, a duvet cover, and a Patagonia fleece.
The app doesn't use money in transactions unless you need to buy extra credits to make a purchase (they call it "winning" an item). Otherwise you give away your own items, get credits, and then use credits to win new items. When you sign up you get 250 credits to start. The way they convert credits to dollars on the site is a little weird so just be careful of that (10 credits = $1). They convert it to dollars to help people recognize the value of things, but it's a little misleading sometimes.
Shipping is paid by the person who wins an item (flat fees of $4, $5, $6). As a the person giving away an item, when someone wins something from you it's your job to print the label generated by Yerdle and drop it off at UPS.
Want to sign up and try it out?
Just got to the website for a link to the app, or from your phone click on this link: yerdle.com/i/ryan-green-135798
Ryan - WickedMint