Can I register a retail boxed copy of a game with Steam?
With the addition of Greenlight to Steam a decent amount of games that were normally purchased elsewhere can now be purchased through Steam. I noticed Project Zomboid was among the titles to be added to Steam. I have already purchased Project Zomboid from Desura, and whenever the game is added to Steam I would like to put it on my Steam account.
Is this possible and how do I do it?