Why Amazon wins

I went last weekend looking for a "powerline internet" thing:

I could have used it that evening so instead of just ordering online (as I typically do) I instead went out to a local retailer:

Not only didn't they have any such item in stock, the young sales guy ("I've only been here 3 months") had never even heard of them.

I tried another retailer that was in the same complex: Fred Meyer. They didn't have it either but tried to be helpful: "Try Target" they said.

I did ... no dice. So I ordered from Amazon, along with several other things I needed ...

No wonder their stock is at $1600 or so ...