If you're an Xbox Live "free" member ready to "strategically dismember" bits of EA because you can't redeem the DLC included in the Dead Space 2 "Collector's Edition", just go ahead and put away the plasma cutter. The redemption card (pictured) gives instructions that won't work for those who aren't Gold members -- but there is a workaround.
An EA rep tells Joystiq that Live free members should go to the "Extras" menu and input the code in the "redeem code" section. This will unlock the single-player Zealot Suit and Zealot Force Gun without the need for a Gold membership. The problem with going through the Online Pass screen is that it's used for multiplayer, which you can't access without a Gold membership. This isn't the first (and likely not the last) time that DLC insert cards have caused confusion.