Overstock.com, also known by its shortcut, O.co, is an American online retailer headquartered in Cottonwood Heights, Utah, near Salt Lake City. CEO Patrick M. Byrne launched the company in 1999.

Overstock.com initially sold surplus and returned merchandise on an online E-commerce marketplace, liquidating the inventories of at least 18 failed dot-com companies at below-wholesale prices. In recent years it has expanded to sell new merchandise, as well.

The business started rebranding in early 2011 as "O.co" to simplify and unify its international operations. However, due to customer confusion over the new name and the .co extension, they are temporarily retracting their rebranding efforts.

Overstock went public in May 2002 at an IPO price of $13, and after achieving significant growth and profits in some early quarters, achieved a profit of $7.7 million in 2009 and reported its first billion-dollar year in 2010.

Read more about Overstock.com:  Business Model, Awards, O.co Coliseum, Sales Taxes, Naked Short Selling Campaign, Lawsuits, SEC and Regulatory Action, Goldman Sachs Documents Naked Short Selling, Board of Directors