I have a Steam product key for Just Cause 2 I got for free with the purchase of my video card. However, I already have a copy of this game attached to my Steam account. What will happen if I try to activate this other key on my account? Will Steam give me a copy of Just Cause 2 to gift to somebody else? Will it simply refuse to add it? Or will it eat the key rendering it worthless?
I don't want to try this only to have the latter happen, but it would be useful to be able to add it and gift it to somebody else.