I see it's on sale and really want to get it! But besides that I also want to have it on Steam.

So my question simply is: Does the GOG version come with a Steam key?

Why am I asking? Well the Steam version can be redeemed on GOG.com

Nope.

They seem to have made other versions redeemable here to drive people to GOG, so a Steam key wouldn't make much sense. Sure, it effectively renders the GOG-buyable version inferior to other versions, but you know. Reasons and stuff.

Doesn't make a lot of sense to me, but it is what it is.

Makes perfect sense. Steam take a cut of all sales. If every gog sale came with steam key they would funneling money to a competitor.

You can always add gog games to steam, just not download them through it.

Every developer I've ever heard weigh in on Steam keys has stated that they're provided to them free of charge, so it would be funneling zero money to their competitor. Instead, they've made buying on Steam the best option since you can buy there—funneling money to Steam instead of GOG in the process—and then redeem the GOG copy here for free, ending up with both versions for the price of one.

Basically, they've made it so that buying anywhere but GOG is the best option. That's what makes no sense to me.

I would love to have a steam key for my witcher games, especially for achievments and cards, sadly gog and cdpr don't seem very receptive to customers and this option.

Uh then why not just buy it on Steam in the first place? Most people who buy from GoG do so for the non-DRM version for a reason.

Exactly, I don't get their desire to get the game on GOG and then ask here for a Steam key.

People this days, I guess with GOG Galaxy the achievement part will be solved for them.

Maybe because most other games allow it? Or maybe someone wants to use the Steam family function? I would also like to have my gog.com games available on Steam. Why? Because why not.

I don't want to sound rude but:

What you're not getting is the fact that this is not the place to ask for a Steam key just because you bought the game in GOG mate, you want to use family function? You can do it with GOG, the fact that other games allow it does not make it a go for GOG/CD Projekt RED products, although in The Witcher case you can buy it on Steam and redeem it here, but obviously not otherwise.

Bottom line is, you want your GOG games in Steam? Add them to Steam, or if necessary re-buy them there.

Happy Week.

and also on GOG you can pick and choose which of the extras you want, on steam it's just one big 7gig dl. This makes the gog version superior in my opinion.

If you purchase the Steam version you can then use the CD key that Steam shows to get the GOG version here for free. I just did it myself. So while it does not work buying it from GOG to get a Steam key, buying it from Steam does give you a GOG key. :)
Use this link to redeem the Steam CD key here at GOG: http://www.gog.com/witcherbackup