Alibaba - the world's largest e-commerce wholesale platform - mainly suitable for selling products, such as clothing, accessories and other daily necessities. Mainly concentrated in the south. The advantages are big brands and many buyers. The disadvantages are too many people doing it. New companies don't have much advantage.

HC360 - China's second largest e-commerce platform - mainly chemical machinery companies, such as excavators and other large machinery. Mainly concentrated in the north. The advantages are strong industry characteristics and strong promotion efforts. The disadvantages are industry limitations. There is basically no market in the south.

ChinaNet - never heard of it.

The above only represents personal opinions.