I have never promoted anything before, but this is a great idea.
If you have coupons or any steam item you wanna get rid of you can drop them in here by trade, (maybe you can find something you will like). Its a really useful tradeBOT.
You can drop/take as much as you like. Like they say, one man's trash is another man's treasure.
http://steamcommunity.com/id/TrashDump/ (no need to add, just use the trade link).

cheers mates.