Catventurer: Your screen shot has "Powered by Rokt" at the bottom-right corner.
If you look up Rokt and Amazon, you will find that Amazon Web Services is one of Rokt's partners.
https://www.rokt.com/aws-partner/
Meaning Amazon gives away free games that they use as a source of advertising revenue. This has nothing to do with GOG, except that Amazon is giving away codes for games sold on GOG.
Lots of us have redeemed codes, either through Doc's giveaway contests (currently on hold due to the sale), The Community Giveaway, or other giveaway contests. Having participated in all of these, I have never once seen a Rokt advert on a code that I redeemed, and that includes the code I redeemed for Dorfromantik that I got from GOG directly from when GOG was doing the giveaway contest. When I purchase games, I do not see Rokt adverts either which includes an order that I made two days ago.
so are you suggesting amazon hacked gOg? because the adds appear on gOg's website, after you redeem the code.