Levi's, thanks to its attention-getting Curve ID jeans campaign, now tops the list of popular denim brands on Facebook with more than 1.6 million fans. Its new denim fit system, launched over the summer, is based on a woman's body shape instead of her size.

The company performed body scans of 60,000 women around the world and identified three main body types -- "slight curve," "demi curve," and "bold curve" -- which the company says fit 80 percent of women. Since July 2010, the all-American brand has topped the list of most-followed denim labels on Facebook.