Both JD & Taobao/Tmall have their own large shipping empires in China. I suspect that was part of the reason they pulled out. They could not compete using 3rd part shipping companies.
Now they are doing the same thing in their home market.
You are correct JD didn't exist back then since it used to be called 360buy and they used 3rd party shipping companies.
After becoming JD they started shipping themselves. Not sure about the year.
Probably right about JD but as far as I know Amazon didn't start doing logistics till after 2013.
Am I wrong about the dates?
In reality logistics is capital and labor intensive industry, Amazon will have trouble once the retail growth flatten but the cost structures are high. Amazon once unionized will have similar challenges and costs like UPS.
This is the reason FedEx never want to be unionized.
I'm not sure about TMall but I know that in Beijing they used to have a distribution point roughly every 10km through the whole city.
When you used to setup your address you selected the closet distribution center to you (I assume because the maps were not setup then. You don't select it any more.)
When I buy packages in Shanghai about half of them are delivered through a 3rd party and the rest are direct. It may just be my area though. I assume it depends where the product is come from...