Based on a question in Quora , I recently did a quick research on the numbers involved and indeed with the explosive growth of m-commerce happening all around ;the overall e-commerce numbers are pretty stunning.
On several blogs and websites a kind of consistent tone emerges that by end of this year the overall transaction amount of e-commerce transactions all over the world will cross the mark of One Trillion Dollars.
I get a lot of information from infographics on this topic from several blogs and I have shared 3 of them in the following link to the quora.com Q&A page. Actually these infographics are really quite informative giving a good geographical spread of the overall e-commerce pie.