Even then, you're looking at similar economics. HBO is willing to pay you $X for your special because you have an audience that is worth (at least) $X to them.

Even then, you're looking at similar economics. HBO is willing to pay you $X for your special because you have an audience that is worth (at least) $X to them. For a lesser known artist or comedian, you lose the power of the distribution channel, but you gain in margins. The opportunity for cross-promotion in the form of an opening act is still alive and well, and I don't see why it can't continue in a digital form.