Ahh, but how many of the 25 million sales of Black Ops were on the PC platform? That's the question.
Ideally, none. I'd like to think that PC gamers are more discerning than that. However, it wouldn't surprise me if there were more pirated copies than sold copies. That said, when you consider that the SP campaign only lasts about 4 hours and that MP is the primary draw of the series (pirated copies can't play online anyway), how many of those pirated copies would have otherwise been $60 sales? That's the important question.