GDP for US Retail Sales est 2009

http://forecasts.org/sales.htm approx 4.2 billion and Total GDP US $13.8 Trillion
http://flagcounter.com/factbook/us#economy

http://www.computerworld.com/s/article/9075759/Online_retail_sales_in_the_U.S._to_hit_204B_in_08

Online Retails sales to reach for 2008 $204 billion