If you didn't already know, for doing certain things each day steam gives you a random gift in your inventory, sometimes its a full game, other times its a coupon, other times its coal.
You can get 3 really easy:
http://store.steampowered.com/holidaysale/
Dec 19th - Click link on that page and you get one free
Dec 21st - Join Steam Holiday Group
Dec 23rd - Trade anyone anything (Just do coal for coal)
(Objectives can still be done after the dates they are unlocked)
ANYWAYS, I'm making this thread in case anyone wants to trade coupons, I know I'm not going to use the ones I currently have, so id even be willing to give them away unless someone has a coupon I might want.
Right now I have:
1 Coal
-25% Valve
-50% From Dust
-50% Magic the Gathering - Duels of the Planeswalker 2012
They don't activate till Jan 2nd however (Lasts from January 2nd, 2012 through March 1st, 2012), I suggest at the very least you do the 2 I listed above cause they are super easy, I know one kid on reddit got Skyrim (full game) from his first gift.