Pretty much everything can be ordered online in China.
There are couple of small grocery shops around each residential compound and the residents normally order online and the shops will bring them to their apartment door step. There is no delivery cost. I think there was a minimum order amount but I cannot recall this now.
I would say delivery service is a lifeline in China. There are probably hundreds of thousands of people who are working in this delivery sector. Here you can see a delivery man catching up on his phone messages below my apartment.