[TulliusCicero]

I'm not sure that's a super meaningful distinction for market power. It's a different method of selling, but ultimately you're selling largely the same things. You probably wouldn't separate out "Ford has this much market share in dealerships vs online sales" most of the time, for example.

[emodendroket]

Well, I suppose that's the key question. But I think that yuo might argue it is, because there's a huge "long tail" of goods that you can only really hope to sell online.

[user3359]

It is. Monopolies only exist within context. Zero to one has a good section on this.