I just wouldn't risk it unless a mod chimes in.
I edited the thread title both times (-> "Stop begging for or trading coupons" -> "STOP begging for or trading coupons") and deleted some of the posts. A few other mods have also deleted posts and I think there was one ban, but that wasn't mine. I'm not speaking on behalf of all mods on this one, just myself, but I think most of the mods who read the thread would see where I'm coming from and a few other mods have deleted posts, like I said. Obviously this is kind of an ad hoc thing, so if things change our reaction might change a bit, and if EL or any admin chimes in with a different take, listen to them.
Here's my input on the situation:
This is basically a thread for conversation about the Steam platform. New client features, upcoming games, sales and deals, game impressions (I especially like these!), technical help. It's a pretty wide umbrella. I like that GAF and the GAFfers on Steam are so great about giving each other gifts all the time. It's amazing how generous people are. And I like to think that people who are the beneficiaries of generosity in turn become more generous. So that's great.
That being said, it causes drama when particular people are always begging for free loot. That's not great. Since the influx of Indie Bundles and Steam coupons, it seems to me like a lot more people are either begging for free stuff, begging for coupons, or trying to trade worthless junk for much higher value items (yo guys got HIB3 key ne1 wanna trade skyrim level crap). That's also not great. Hey, I've got plenty of free stuff on GAF too, I have no problem with people wanting free stuff, but it needs to be tactful, it needs to not cause bitterness and resentment, and it needs to stop flooding the thread.
That's why I first asked people to not beg for coupons in here. Then to not trade coupons--because "I want Skyrim 50% off" and "I want Skyrim 50% off am offering 10% off Focus Home Interactive" are the same thing. We have a trading thread that's setup to accommodate that without getting in the way of discussion, and without really any real need to worry about chronic beggars or problem users. I know most people mean well, but this is the best solution for everyone.
With all that in mind as where I'm coming from, I haven't in the past stopped people from giving stuff away. Sometimes it gets annoying when like 5 people hold back to back giveaway contests and the whole thread is contest entries, but in general someone simply saying "Free Bad Rats Code: 1847-GYJB-FART" and someone else saying "Thanks, claimed" is okay. If a lot of the users in this thread feel that stuff is obnoxious, then maybe we could start taking a look at moving it but for now I'm not too concerned. Clearly people offloading their junk coupons is a bit spammy, like donating clothes with holes in them to a thrift store and claiming you're charitable, but for now I don't think it's been a problem here.
In an effort to keep the thread on track, if you read this and don't have anything urgent to say that needs to be said in thread, please PM me or another mod instead of replying in here. I'm always happy to hear feedback about this thread in particular, it's one of the best ongoing threads on GAF in my opinion.