What a surprise to learn that Time Inc. is shutting down Teen People in September. It is hard to imagine an idea with more market potential. Take one of America’s most popular magazines, which focuses on America’s most popular people, and gear it to teens who are the prime target market for every advertiser. An instant recipe for success.

So what happened? According to the New York Times, both circulation and advertising were dropping, which meant the magazine was losing money. But why?

It could be as the Times speculated. The marketplace is too crowded with celebrity news, since both Celebrity Living and Elle Girl closed earlier this year. Or maybe it’s because advertisers are diverting their ad dollars online where more and more teens are congregating. Or maybe it’s because teens are simply reading less than they used to. That’s an ominous trend for all teen media and the adult print media waiting for them to grow up. Or maybe it’s something else.

Is it remotely possible that teenage Americans are losing interest in celebrities? Is it conceivable that kids are getting tired of reading about how much Nicole Richie weighs and who Nick Lachey is dating?

This is difficult to fathom. But perhaps the desire for authenticity is penetrating the younger demographic. Maybe the adults of tomorrow are becoming more interested in each other’s lives than those in Hollywood. Maybe they are finding communication with peers on MySpace is more satisfying than reading about Lindsay Lohan. Maybe the real world is becoming as fascinating as the celebrity world.

If this trend is real, it could pose an enormous future challenge for the companies that rely on celebrities to promote their products. In fact, just this week Versace launched their new ad campaign, which eschewed Madonna for the old-fashioned fashion model. It also wouldn’t bode well for celebrity publicists. If fan magazines continue to shutter, publicists are going to have a lot fewer covers to negotiate for their star clientele.

Teen People’s demise is probably just a speed bump on the Hollywood freeway of fame and fortune. Or maybe it is the beginning of a subtle shift of America’s youth toward more authentic content. The coming years will confirm if there will be more Paris Hiltons or more Holiday Inns.