New York

IVY Park, a new fashion line from Beyonce Knowles, seems to have everything going for it. It's a premium activewear label with an unabashedly on-trend mix of sleek workout gear and casual clothing. And of course, it has the superstar power of Queen Bey herself and a built-in market of fiercely loyal fans, the Beyhive.

But Ivy Park's success may not be as inevitable as one might think. Even Beyonce will have to struggle to avoid having it join the dead or dying celebrity brands that litter the landscape.