Nope,he is referring to Steam trade system (gift,not keys).
Gog can be allow the purchase of a single copy of the game without key,to trade thanks to a inner trade system on the site.So there won't be key to redeem and the one who already own that game can't redeem the gift.

Yeah it does. You click the trade button and it opens a window split in half. You put your items in one window and they put theirs in the other. Then click ok and the other person has to do the same thing. Once done items get swapped between accounts and done. Prompts you while you are doing it making you click ok and next to make sure you are fully aware of what you are doing. System works really well and stops you getting ripped off.

They could make trading system for GOG gifts, though.
You can trade only items from your inventory this way.

People on GOG usually trade steam keys, desura keys, gamersgate gifts etc and it's just simply impossible to make a system that would cover that.

Impossible from GOG's end, because why would they encourage Steam keys trade, if it's not legally clear?

I gave up steam trading a long while back (hadn't done many of it either). I don't think there were any mechanism for KEY trading. People either refused to trade keys, or found trust worthy middle man.

Worst case scenario, we'll also need to adapt the middle man way here. The side receiving offer finds trust worthy middle man (to avoid "offerer" impersonating middle man).
I'll hate to see that though. One of reason I still trade here (occasionally) is the trust between people, that is not going to be a good indication. (kinda also why I give up trading on steam forum, too many scammer reports, too little trust)
I understand, but people usually get scammed while trading keys, more often steam keys from bundles or Amazon.

They're not keys, mate. The games you can trade are called gifts.

The easiest way is to display forum Rep and registration date in PM window

and GOG should be able to do that rather easily...

Makes sense that my rep has been going up and down Like a yoyo now!

Must be the scammer doing it?

I think I know who the scammer is he is the same arsehole who posts shit on my yahoo account who I Dobbed into IC3 IM HAPPY that I know they will be caught

Yeah, of course. You buy extra copies of stuff and it sits in an inventory where you can either trade it or add it to your own account.

My point is that there is a system there that works well at protecting you from getting scammed / ripped off.

Thing is with GOG its done with gift keys where the trade is done on a kind few words and a digital type handshake when coming to do a trade with another user. Unfortunately its easier to get ripped off by these social engineers when trading in this way.

Its such a shame as there are some great members here, completely trustworthy users from all over the globe. We are all here as we love PC gaming in one way or another, granted there are threads going on about Steam and the likes but in a way we are all united with the same passion towards gaming regardless.

If you got ripped off in the same way on your doorstep you can do something about it under local law, sure it sits under obtaining goods by deception and if the person doing it gets caught they can be fined and imprisoned for it in the UK.

Thanks guys for finally managing to sort this piece of work out, took a little time but well done :)

I was scammed a copy of Bards Tale on Steam out of him so its my own fault for not picking up on the slight username change.

Nice one... but also remember to phone call his mom!..
(this will grant him some months without TV and chocolate porridge...)

yeah, and not only in that...

If you don't mind me asking who was this scammer.

'twas a wicked man, a character most heinous.