Advertising has, for decades, worked under the presumption that the 18-49 age market dominates purchasing power and drives culture, so they are the primary targets of most ad campaigns. Sure, you don’t see ads for adult diapers aimed at young people, but that’s a niche market. Anything more general and broad tends to be targeted at this demographic.

This has been the consensus view of marketing for a long time now, and it never has made any sense to me.  I remember being 18-25, and I never had much money.  I remember well being in college and almost no one had any money.  We drove beaters and ate fried Spam because it’s all we could afford, not because it was hip and trendy.