Historically, all the large retailers like Walmart and Sears have been brick and mortar entities. As expected, the Internet is slowly changing this. A recent article on Fortune listing top retailers now has Amazon in the top 10. I suspect other online retailers may eventually be included on the list as well.
I also think it would be interesting to know what percentage of sales large brick and mortar retailers like Walmart make online. If I ever find that out, I will be posting that information as well.
On a related note, Amazon has made a lot of waves recently with Prime Day, which I wrote about in this Amazon post.