I call BS on that number.
Not once have I ever been asked who I'm purchasing a game for (my 7 year old daughter, birthday presents for cousins, friends kids, etc).
Not once have I ever been carded when buying a game or asked for my age.
Not once have I ever seen or taken a survey asking me questions along these lines.
So where are they getting their numbers from?
How many kids do you know that don't play video games?
How many pre-teens, tweens and teens do you see taking survey's?
If the survey was done online, was it a site that pre-teens, tweens and teens surf often?
If the average gamer is 30 then why has Nintendo cornered the market with "kiddie" games?
You could point out how well M rated games sell, and I could point out a lot of parents who purchase those games for their teenagers.
Why does everybody on here always complain about all the young teens on x-box live and other online services?
If the average gamer was 30 wouldn't most the people on those services be 30 and not 14?
I could go on forever.
I bet there are as many kids from age 3 to 17 that play games as there are 18 to 32 year olds.