Are you planning to buy SimCity (physical copy), Dead Space 3, Crysis 3, or Army of Two: The Devil's Cartel before launch? Amazon is throwing in a $20 credit on all four titles, which I don't need to tell you is strongly worth considering. Additionally, the retailer has a $10 credit for pre-orders of God of War: Ascension going on right now.
These promotional credit offers are included on top of any game-specific bonuses Amazon already has for pre-orderers, such as exclusive weapons and characters for multiplayer. After hearing about SimCity from Hamza today, I might have to cave.