Japan's Rakuten: Can The Biggest E-Commerce Site You Never Heard Of Become a Threat for Amazon Globally? The term “e-commerce” still lacks a universally valid definition, but even if you just bundle B2B and B2C transactions under it, it’s a multi-trillion dollar business globally. Last year, Nielsen found [PDF] 86% of the global web population made an online purchase already (North America: 92%).