I go to comic shops all over New York, which is a nexus for them. I haven't seen anyone under 21, or probably even under 18, read or buy any non-Manga, non SCOTT PILGRIM comic that wasn't handed to them physically by a parent, usually a dad, usually buying a dozen Big Two comics for himself. It has been a topic of endless articles why the same kids who watch cartoons, enjoy the toys, movies, video games of comic characters don't and will NEVER pick up an actual comic book of them. How can a Spidey game sell millions of copies at $40 a pop but a comic at $3 won't even sell 100k? There's an inability to bridge the gap between media. Some have even argued that monthly comics are in a "disco" faze now, a dying fad that will be replaced by technology in X amount of years (this I personally don't buy).
I sometimes see kids at comic conventions, but are they alone? They're there with their parents, and usually bored out of their minds. There was one scene in I think 1997-1999 or so that was symbolic. I went to a card show in Brooklyn that also had comics there and I saw a dad with his kid there. The dad was going nuts collecting trades and back issues. The kid was bored out of his skull playing Pokemon on his Game Boy Color. Now that kid would be about 16. I'd bet money he hasn't read comics, but his dad still is. The problem is dad will eventually stop, either economics or death. Unless the hobby passes the generational gap, it's gone for that family.