Where's your fragging logic, Activision? Going away from the numbers and whether or not this is true, how is that an accomplishment?
Your AAA-super budget title with giant marketing campaign and a loyal fanbase has more players than a browser based indie title? Well big fragging deal.
Transformers 3 was watched by more people than those who have read I am Robot, but where's the comparison? There are quite likely people who like both, but in many cases, those who like to play Zynga-style timekilling games like Farmville will not enjoy being repeatedly shot in the face with a HK-PSG 1 from half the map away just after spawning, because they most likely will not be into FPS games.
I am going off on generalizations for the sake of a point here. There are gamers that like both, but there is most likely the majority of Facebook app fans who don't own a gaming console or don't play Call of Duty competitively.