Here is an update to our article referenced by Business Insider. Walmart.com sells 4,417,344 products as of Sep 30, 2015, out of which most products are NOT sold at Walmart itself. If you drill down further…
UPDATE (April 2017): Please find the updated post here
Walmart.com sells 4,259,605 products
Amazon.com sells 356,227,986 products
Walmart.com sells a mere 1.1% of what Amazon.com sells
This is an interesting point of comparison on how online and offline retailers compare to each other. Rather, how the the online sites of “brick and mortar” stores compare to pure online stores.
It is a small percentage and shows you how much ground Walmart has to cover to catch up to Amazon.