Here is a very interesting look at the Back to School season by Margaret Webb Pressler at the Washington Post. Back to School is a difficult season for retailers because teens can be very fickle and fashion trends can appear and dissppear remarkably quickly:

It is also one season that really keeps retailers on their toes, because if there's one thing that teens seem to agree on, it's that you can't commit to a look too early.

"A lot of the kids wait to buy their school wardrobe until they get to school to see what everybody is wearing," said David Hacker, trend director for women's sportswear for J.C. Penney. "That's when they drive the volume."

...None of this research and advertising, though, can protect against that most fleeting of fashion influences: the popular teens. When kids go back to school, they may notice that a leader in their group has come up with his own idea, perhaps something picked up from a CD cover. Immediately, the followers run to the mall to try and duplicate it, marking the second wave of back-to-school shopping that all retailers wait for.

Pressler suggests there are two basic strategies for attacking the back to school market. Retailers like J.C. Penney begin researching fashion trends up to a year in advance and testing small samples of the new merchandise in the spring, hoping they've caught a fashion wave they can ride in September. Then there are reailers like Old Navy who don't want to take any chances and set out to create the fashion trend themselves:

This year for back-to-school, Old Navy is promoting rugby shirts for the whole family, complete with commercials about the "Rugby Bunch" all-American family. "We're getting behind a product that we feel our customers are going to respond to and be very comfortable with," said Jonathan Finn, director of public relations for the company.

But Old Navy doesn't just hope. The saturation ad campaign is also meant to create a de facto trend in the collective teen mind.

"If you can't get everyone in school to wear it but you can get it all over TV, maybe that'll be the influencing factor," said Cohen of NPD. "Eventually, people will say, 'I can wear that, because I've seen it.' . . . That's the logic with these barrage campaigns."