I'm not sure I've understood it, but my suggestion is not to force anyone's hand, it's simply a way to make achievements more attractive as many people find them useless.
In this way there would be a small prize for those who take the trouble to complete them, while those who are not interested would still have available the basic background of the game.

More than anything I proposed it because many games have more than one very nice artwork and would add variety of choice. Happy that you like the idea of backgrounds based on past sales.

Not everyone can complete all achievements - some are very grindy, others beat that on hard mode, etc.; it consumes time and if you're the type who beat a game then move on to next one, you'll miss this one as well.
So you're force to invest more time and/or keep trying, otherwise you'd just sit with one background per game despite owning the same thing as others.

As you said, not everyone is into achievements; but one might still be interested in that certain wallpaper regardless.
They shouldn't need to go through all that to get those.

Agreed, so why not make them readily available for everyone?

And yet you decided not to add my suggestion to include the possibility to deactivate one's profile completely. I think that's a reasonable suggestion, so please add it!

1) screenshot upload (gallery)
2)video recording (i know win10 has it, but its buggy mess....)
3)better privacy settings (change the opt out we have now with opt in)
4)maybe.....gog should have achievements first before making a profile about achievements.....most games dont have them even if the same games have them on steam. I WANT FALLOUT 3 ACHIEVEMENTS (yes, i am aware that the steam version has no achievements ...)

I know BK doesn't want this thread to be used for arguing and I'm not really arguing I am just pointing out that Gog have cleary gone to a lot of effort and expense to create this and no doubt have more in the pipeline. There are sound commercial reasons they want people to use it. However people feel about it they are very unlikely to give the option of completey deactivating it. Your request may be reasonable but so is their need to make their website more attractive to more people and attempt to improve it for those already using it.

Minor Issue: Profile is not synchronized between web and Galaxy client; activity feed shows all unread on Galaxy in spite of having read on web. (This obviously fixes itself, it is still a baffling flaw.)

First off I have not added anyone's ideas since I last said I have added everything above. So I don't know why you feel singled out here? I add them when I have time and when I'm at my PC (and not on mobile). I will update them later today.

Having said that, I have already added ideas that would allow being able to completly hide pretty much everything on ones profile to effectivly make everything private and hidden. This would essentially be deactivating ones profile. So yea I may draw the line where suggestions start becoming similar to conserve space.

It seems that this has been fixed (see attachment).

Bug (penumbra case):
The number of games on the profile doesn't match numbers in the library.

Type: Bug

Posts from activity feed don't get removed after you unfriend someone.

Type: Bug
Description: Number of owned games do not update realtime.
I bought Spellcasting 1+2+3 and the number only increase in https://www.gog.com/account
After hours, the count in profile still unchanged.

Thanks to everyone posting, I know I said I would update this yesterday, but I didn't have time. Will update the OP either today or over the weekend.

How about this one? A count of time spent logged into Gog? Yep! It could become embarrassing.

What's embarassing about 24/7?

Type: Bug / Issue

I just noticed a massive oversight. If somebody has their friendslist hidden, you can still see some of their friends so long as their main profile is visible. They're listed in the "friends" area under the "recently played" bit.