But that's a bit of a ridiculous assumption. I'm actually quite surprised at you French.
Modern Warfare 2 has to be installed through Steam. Parties are formed, invites sent and games joined through Steam. Text and voice chat through Steam. There's absolutely no reason for people to be running xFire if they're playing MW2. Which means that playstats won't be tracked accurately. One could just as easily twist it the other way and say that according to the
Steam stats MW2 had a peak of 95000 players, whereas MW only had 534, therefore CoD4 is failing to satisfy (on an enormous scale I might add) the level of complexity and interaction PC gamers demand from their multiplayer experience.
And considering only 6% of MW2 sales were for the PC I don't think Infinity Ward will be too pissed off at themselves.