Thanks bro. That was really helping. =P
Now I know why I always have to "Go First".

Hi , i have a Witcher 3 Wild Hunt Key, i wan to exchange it for a Witcher 3 Wild Hunt Expansion Pass ! Let me know if anyone is interested.

You are right, but the question is that he does not trade with a GOG user. He traded with a Steam user. He did not even know the username of the GOG user (if the other have a GOG user, maybe the other do not have a user in GOG), so he don't know anything about the other user rep.
He traded on Steam for a GOG key. That's all. No trade between GOG users.
I have traded a lot with GOG users and never have any problem.

Added (Steam)

Shovel Knight
Super Hexagon
Dungeon Hearts
http://www.gog.com/forum/general/gogs_general_trading_thread/post5843
Thank You for looking and have a great day :)

rep is not that important, as the list of successful trades is!

Oh darn, I need just a bit more activity here before I fit the bill for your (hypothetical) trustworthy status. =P

Bump

I'd be willing to trade all 6 of my games for something on my want list, if desired. Especially Grimrock 2, since it's on sale for $12 on HB (yesterday's deals)!

Closed for trading

Have:

Nothing

*= games can not be separated from key
^= Gog Connect eligible title

Want:

Nothing

tags: #BenKiitradepost, #CommanderBenKii, #BenKii, #post6290, #CaptainBenKii

Confirmed trades:
VIPERs
sasuke12
jimnorth
yarow12
huN73R
X-com
koima57
misterlion
Killimanjaro
Rexoberan
MysterD
Getcomposted
PainOfSalvation
geekgamer
KoreaBeat
GR00T
koima57 (2nd)
Ogdin
DeaniKris
wanderer_27
paladin181
apehater
DebbieL
DebbieL (2nd)
madth3
wanderer_27 (2nd)
Ogdin (2nd)
z02228

Yep so shut up and start posting some quality content so you can fit the bill for my trustworthy status. 152 more rep to go. COME ON! YOU CAN DO IT! DO IT! DO IT NOW!

Edit: many thanks to cecil for the trade! :)

I agree that a list of successful trades can prove that someone is trust worthy(depending on the games that were traded). A list showing you successfully traded away a bunch of cheap Humble Bundle games doesn't prove anything because who would scam someone for a cheap game? The list should show that games of high value were successfully traded away.

How is GOG supposed to know for sure that this was a scam? Because one party of the trade says so? GOG has no way of knowing what happened during that trade. Even if you provide screenshots, there is no proof that you haven't received something in return through other means.

GOG is not responsible for you not doing your homework and taking risks you shouldn't have. Sorry if that sounds harsh. But trading of games is a grey area, it is not officially supported, and it comes with risks, _especially_ if you do i with total strangers. There are some very easy precautions that help mitigate the risks, but if you don't take those, don't expect third parties to stand in for your mistakes.

One of those precautions is "Don't go first in deals with strangers; if you do, always be aware that you may end up giving your stuff away for nothing in return. If you don't have the standing to ask the other party to go first, choose a middleman that you both trust. Otherwise, if you care about your stuff, simply don't make that trade.

99% of scams could be prevented if people just made a proper risk assessment, and were able to say "No, I'd rather wait for a safer offer."

I was thinking about this and a thought just came to me. We call it trading so it has an air of legitimacy, but we're basically a black market. After all the whole purpose of keys is that they're supposed to be gifts, not a commodity.

Um, no. A black market is illegal trading, forbidden by law and a grey market is legal but generally unwanted by authorities. Neither is this here, but simple non-commercial bartering. The only thing to discuss is whether there's a violation in GOG's user agreement.
Gifting is explicitly allowed by GOG and selling or charging money for gift keys is explicitly forbidden. Bartering isn't regulated and from GOG's point of view treated as gifting. That means, if somebody sends a code, from GOG's point of view it's a gift. A real barter is only completed when both parties receive their goods. Only then the ownership of goods changes. When one party doesn't fulfil its part (here a.k.a scamming), GOG, as the service provider, would be involved in solving the issue if they'd acknowledge it as bartering. But as they're going with gifting, they're out of the game. From a commercial point of view, there's no drawback for GOG. On the contrary. The games are still exclusively sold B2C by GOG and gifting allows for customers to buy more than one key of a game, what would be impossible otherwise. Further GOG generates revenues where they normally wouldn't without gift codes. E.g. due to people trading Steam keys for GOG games, which they couldn't afford otherwise, not to forget a happy community who appreciates the flexibility - seldom to achieve with so little effort ;-)