No matter what the cost of a new warehouse, a distribution center or even hiring your own delivery service (which Vancl has done), these companies will spend whatever it takes to be the number one player in their space.
For cost efficiency, best pricing to customers and freshest product delivery, they manage to create a scenario where products rarely stay in the warehouse for more than a week.
The advantage for Chinese buyers is that goods are mailed to a warehouse in Dallas and bulk-shipped to China, saving on postage costs, with 10 to 14 days of delivery time.