I think the bigger problem is the game itself. The game is basically an amusement, and if you get your fill of it before you're done, there's no way you're going to buy it. I don't want to make it sound like I think this is a bad game, even though I've had some negative comments in the past, because I totally don't think that. I think it's a tremendously awesome game in every respect and I more than got my money's worth. However, it does suffer from that "Wow, that's cool! But I think I'm done now" problem. A lot of games you can see downloading and being totally into, then buying after because you like them so much, but I think with this one a lot of people come for the control scheme, come for the fun climbing on stuff, come for the shanking... but then they finish with that really fast and feel no need to continue playing. I've gotten that from a whole lot of the people I've talked to, and that's pretty much how it was for me. I'm curious about the story, and maybe I'll finish someday, but that was never my driving force, and I don't think it was for anyone else either (even though the plot *is* cool, nicely presented, and potentially quite interesting).
I don't know about the rest of it, but I think that's a big problem for this game. It's just too easy for it to lose its allure. But I still think it's a bit bullshit, because this is primarily a console game, and I'd venture to guess that a ton of the people who downloaded it simply wanted to check out how it ran on PC and what new features it had. Seriously, I'd bet that's a good 25% of the people who downloaded it.