Take a look at this article in the USA/Today Business section from 10/11/06:
Yet another look at the Echo Generation of the Baby Boomers more commonly known as Generation Y. They are as big or perhaps bigger than the Boomers and they have their whole life ahead of them to spend spend and spend. The big advertisers are all going after them in any way they can dream up.
Too bad radio has it's head buried in the 25-54 sands and won't even try to get this generation interested. Their radio usage is dropping like a stone and every day you see more stations jumping on the 25-54 bandwagon. We could still appeal to this audience - it will take some risks, creativity and investment. Most of all it will take thinking outside the box and also a ratings system that acutally reaches this group in it's sample.