The closest data I could find to answer your question can be found here http://www.bizreport.com/2008/02/forrester_online_shopping_growth_to_slow.html
According to the article + research, $175 Million Dollars was spent online in 2007. I strongly suspect that the correct figure is in Billions, not Millions, as moments later the article provides an estimate of $204 Billion Dollars for 2008, and $235 Billion in 2009. Hope this helps.
