ModCloth is one of those classic startup success stories that produces a company that barely resembles its original self. That's especially true for the Pittsburgh-based, vintage clothing e-tailer. After all, it was only 2006 when Eric and Susan Greg Koger graduated from Carnegie Mellon University, got married, and husband sold his stake in  a web development and consulting outfit. Nowadays, it's the fastest growing retailer in the country according to the Inc. 5000 list of the fastest growing companies. It has grown from $90,000 in sales in 2006 to $15.5 million in 2009. The company has 13,000 followers on Twitter and more than 30,000 fans on Facebook. More than 150,000 web pages link to ModCloth.com, and if you search for indie clothing, retro clothing or vintage outfits, ModCloth is your No. 1 Google result for all three.

The company, founded in 2002, now has 100 employees who contribute to the nation's foremost authority on indie clothing. ModCloth got this far thanks to a broad selection of affordable and hard-to-find women's fashions and accessories, engaging promotions on its blog and social networks, and a devoted following that loves its vivid product descriptions. The regular "Last Hurrah Sale" feature is always a big hit, and ModCloth also allows users to "Be the Buyer" and help the company choose which designs get created. In a difficult market, the company also raised nearly $20 million from investors and moved its headquarters to San Francisco by the summer of 2010. Its distribution center, however, remains in Pittsburgh, where the vast majority of its staff and core functions remain.