gyokzoli: Puzzle Quest 2 You get only the key which must be registered on Steam. And you can't download it from D2D, you must use Steam to download.
Amazon sells Civilization 5 or Empire Total War both of which require Steamworks in a box, but actually the only valuable thing they sell is the Steam key, the disc is just to put in the shelf or to bypass initial downloads.
Its common and the only way to sell games that are integrated in Steams gaming plattform Steamworks (not the shop itself) outside of the Steam shop.
I guess its okay for D2D to do this since it increases price competition a little bit. However only, if the publisher doesn't set the price for all shops (in Europe vertical price bindings are actually not allowed).
Indeed it works: Puzzle Quest 2 is 0.3% cheaper on D2D. :lol: :)