Online car-buying platform provider Zag recently announced that its online auto listing and car-buying service client sites such as AAA, USAA, Overstock and American Express, have sold more than 100,000 vehicles since its 2006 launch. The company reached profitability in August 2009.

The 100,000th vehicle was sold by Mercedes-Benz of Fort Washington, PA. The customer realized a savign of $704 off the MSRP for his new 2010 M-Class. Zag leverages group purchasing power with dealers, and the dealers provide a low upfront price guarantee on fully loaded vehicles while the consumers are still on the Zag site.

“Zag continues to thrive because its platform has aligned the interests of both consumers and dealers, removing the long-standing suspicion behind this commonly-dreaded interaction by providing consumers with low upfront car prices and a haggle free car-buying experience,” said Scott Painter, CEO and founder of Zag, in the announcement. “Consumers save on average nearly $2000 off of MSRP and affinity consumers report 95 percent customer satisfaction with their Zag-owered auto buying program.

Zag fees to dealers are pay for performance. Based in Santa Monica, Calif., Zag was recently named the second fastest-growing company in Los Angeles County by the Los Angeles Business Journal. USAA has been part owner since Feb., 2009.