I am pretty sure they have thought about it... but I also think that they hope that some of them fall into the hands of people who wouldn't buy it, and they would thus start to play it and maybe buy other games as well. A good way to keep the casual fans of the page interested.
Not much use for me personally. I didn't win the boxed copy, and I have little need for the downloaded version. But I can always give it to someone who doesn't have it, if I win.
Paradox is just too good ! You can even trade it to some other title if you already have CK !