The Wall Street Journal has produced an excellent, graphics-heavy introduction to China’s e-commerce giant, which conducted US$240 billion in online business in 2013 (more than Amazon and E-bay combined). The informal definition at the beginning explains why you should care:
Alibaba is China’s — and by some measures, the world’s — biggest online commerce company. Its three main sites — Taobao, Tmall and Alibaba.com — have hundreds of millions of users, and host millions of merchants and businesses. Alibaba handles more business than any other e-commerce company.
Alibaba’s forthcoming IPO is expected to value it at between US$150-250 billion (placing it among the ten most valuable tech companies in the world). The rapidity of change in this sector is difficult to grasp. The US$300 billion Chinese e-commerce market is expected to exceed US$700 billion in 2017.
ADDED: Some background on the Alibaba-Yahoo relationship.