I'm not sure how many teenagers browse my websites, but I suspect they don't make me much money. Although I can not point to one right now, I know there are studies showing that most web traffic comes from offices during working hours. Looking at my stats - the peak hours are between 10 am and 12pm. Wouldn't many of today's teenagers work in an office 10 years from now? And wouldn't they be in front of a desktop computer while at the office? Or maybe laptop or pad, but it would have to be a big screen computer for them to be able to get some work done.
My point is I don't see why teen computer habits are at all relevant here.