B2B E-Commerce Statistics: $559 Billion By End of 2013

We had spotted multiple mcommerce stats in the past - we have always wanted to size up the B2B market overall - it is over a half trillion dollars overall (Source)

There is obviously a lot of cross-counting happening here, in between this, cloud computing, and IT stats overall. But the size is significant, and it is surprising why so many players focus on the B2C segment.