US teenagers and young adults spend almost 17 hours a week on the Internet, six times the national average,¹ yet advertisers continue to allocate a disproportionate share of teen-related ad spending to traditional media (exhibit). One cause for the mismatch is the online behavior of teens: e-mail, instant messaging, and games don't support banner ads as effectively as shopping or surfing do.

The response of most media companies has been unimaginative—tightening the integration of off- and online content in hopes of driving traffic from hit TV shows to ad-supported Web sites. Some, however, are experimenting with novel payment schemes, such as AOL's prepaid My Plastic card, that give teens more independence to make purchases when shopping online. But rudimentary cross-media measurement data are thwarting the attempts of media companies to develop next-generation ad strategies for teenagers. New approaches—involving, say, product placement or advanced viral marketing—will require better information to help media companies understand this rapidly evolving market and to assess the financial impact of their marketing investments accurately.