Giulia Pugliese is a typical teenager. She likes to look good. And she's particular about what she wears. But when the 15-year-old girl from Long Island went on a back-to-school shopping trip with friends, she left a Nike store empty-handed--- even though Nike is one of her favorites. The reason?
  "I buy on sale because it's stupid to buy a pair of shorts for $60," said Pugliese, who instead looks for the "Swoosh" logo in discount stores like Marshalls.
   Teens are shopping like their parents during the back-to-school season. When they shop, they spend less. When they do buy, they're less likely to get anything that's not on sale. Today's kids recycle more clothes from the previous school year, mixing and matching the old with the new for different looks.
  Teens' behavior is an extension of how their parents learned to shop since 2008 when retailers pushed discounts to entice people to buy during the downturn. That helped absorb shoppers. But it also got them addicted to deals. The shift made it difficult for stores to make money because discounts cut into profits.
  Such behavior has cut into sales from July through September, the second biggest shopping period of the year behind the winter holidays. Sales during that period were 24.9 percent of total sales annually last year, down from 25.8 percent in 2003, according to The Retail Economist.
  "Consumers are sending a message to retailers that says 'the back-to-school shopping season just isn't that important any more,'" says Deloitte's Alison Paul.
  The shift is changing how stores market to teens. Whereas stores' promotions would end around Labor Day, they're now extending them through September. They're also pulling together complete outfits from different brands in stores to make it easier for teens to buy and choose. And they're using social media campaigns to be more easily discovered by teens.