The biggest challenge they have is that the defining characteristic of millennials is, there is no defining characteristic. Marketers desperately want millennials to be more monolithic, but the older end are parents with a couple kids, the younger end is just getting out of college. It's the most culturally diverse group, and they celebrate that. Media companies struggle with mass-culture segmenting. You can't be all things to all people. We're no longer thinking in large, demographic swaths. We're thinking of coalitions of like-minded groups.