ummm it doesn't really count in a survival situation if you are 3 feet from the target.
Also since you are likely to only get a single throw you are better off with something a lot bigger then a small nail. Something like a javalin or short spear will not only cause more damage but it can be thrown more accurately from a much further distance (allowing the chance to get a valuable second throw) AND is a more effective CQ weapon.
Really though, just buy a gun or even a crossbow, pussies. Hell, a slingshot would be more deadly in the hands of these yahoos.
I used to laugh at a friend of mine who does occasional mountain man weekend contests with tomahawk and knife throwing, but hell all those groups could at least stick in the damn targets more than 30% of the time