Can use cd-key from retail version of Witcher 3 to download from gog.com or steam?

I've just ordered Witcher 3 for PC from Amazon but I didn't realize that it comes on bluray (at least what the description says) and my PC does not have bluray reader. Will I be able to download it from gog.com or Steam using cd-key that came with the game?

Solution 1:

All retail versions of the Witcher 3 contain a GOG key:

Each retail PC copy of Wild Hunt will contain an additional GOG.com game code for The Witcher 3: Wild Hunt. One can install and play the game without the game code and without becoming a GOG.com user.

GOG.com game code grants access to a digital backup copy of The Witcher 3: Wild Hunt on GOG.com and to full software support, i.e. future updates, as well as all the additional content like the 16 Free DLCs, the FLAC & MP3 soundtrack, comics, wallpapers, art book, all voice over packs and more.