Are online stores as simple as blog + inventory + accepting credit cards?

I don't mean the platform is simple. Or that implementing a store builder is simple. But the concept and the interface from the end user (store owner) point of view. Basically, if you can create a Tumbler or Wordpress blog and have a list of products, can you have a store?

It would seem so.

Pretty amazing how tech can remove frictions. And yet my cable box still uses as much electricity as my fridge and the remote has more buttons that a small plane.