360 Voice GTA IV stats
that 30% of their members
GTA IV in the first 24 hours of release.
Other interesting facts:
The second biggest day for a game ever, beaten only by Halo 3 launch which had about 5600 more players.
Call of Duty lost about 40% of it's gamers for the day
Halo 3 which saw a similar 37% drop in players