The 360 is Nike's first shoe to eliminate foam from the middle sole and replace it with air. Unlike foam, air doesn't lose its shape or cushioning. The air sole holds up better than the foam sole, but the rest of the shoe goes through the same wear and tear as a foam shoe, says Jeff Pisciotta, Nike's senior researcher. "This is about trying to get people to run faster, better and longer and about minimizing the risk of injuries."

Despite Nike's push for performance, buyers will be more interested in form than function, says John Horan, publisher, Sporting Goods Intelligence. "They will sell 95% of them to guys and women who think they look cool with their jeans," Horan says. Looking cool might be more important than running faster. While 34% of all basketball shoes are used to play basketball, 22% of running shoes are used for running, says Marshal Cohen, chief retail analyst at NPD.