Players/Big Three Media Ownership

The Publishing Layer — Books and Academia

Even the alternatives have the same owner

Penguin Random House (Bertelsmann): Private, but distribution through Amazon (Vanguard 6.6%, BlackRock 5.7%). HarperCollins (News Corp): Vanguard 10.2%, BlackRock 7.6%.

Also in Big Three Media Ownership

The Distribution Layer — Platforms Are Also OwnedAll PlayersThe Advertising Layer — Revenue as Editorial Control