Marketers spend many millions trying to capture the eyeballs of today's youth. What are they learning about the current and -- more important -- future spending habits of this generation?

Ross Rubin of Reticle Research moderated a youth-led panel at the recent "Engadget+gdgt Live" conference in New York City. He spoke with Motley Fool analyst Rex Moore about one thing Facebook (META -4.13%) should worry about, and one thing it's doing right.