Zappos.com's story reads like many dot.com startups. Founder Nick Swinmurn couldn't find a pair of shoes he desperately wanted at local stores or even on the Net. So, in 1999, he founded Zappos to spare others his frustration. His timing was perfect. Zappos' gross sales have increased at a compound annual rate of 119% to an estimated $1 billion this year, making it the No.1 Internet shoe business.

And like many dot.com startups, Zappos rapid growth meant some responsibilities, such as finance, were handled on an ad-hoc basis, rather than through formal arrangements. But with soaring sales and climbing inventory (Zappos stocks approximately 3 million products: shoes apparel, handbags and accessories), the suburban Las Vegas-based success story needed a world-class financial organization.

Amanda Nevins, chief accounting officer and vice president of finance, took on the weighty task of creating accounting, finance and treasury departments–virtually from scratch. "The lack of structure in some ways actually made the process easier," says Daniel Simmons, director of treasury and risk management, one of Nevins' first hires in Treasury. "With a blank canvas, we had a lot of opportunity to create things," he notes.