Right not a bad point, but I was making the comparison to demonstrate Amazon's scale within ecommerce... not to compare the volume of sales across all commerce.
I personally think the distinction matters, but maybe I'm wrong.
The other issue with your distinction is that all these brick-and-motor retailers also have online eCommerce services where shopping carts, logging data, and third party vendors are involved in improving the experience - and let me tell you, those guys are using the data. Probably not nearly as well as Amazon uses theirs, but they're still trying as best they can.
I personally think the distinction matters, but maybe I'm wrong.