FB has Audience Network which extends their targeting off platform.

But yes, Google’s acquisition of Doubleclick and investment in video through YouTube has allowed them to capture the publisher and buyer side of much of the open web (and use the data to cut out competition - cf. Project Bernanke)

Yeah the figure I had in mind before looking for sources was 95%, which might have been a couple of years ago. There still is a chasm between how they make money and how people think they do. Probably because ads and tracking are more or less background noise when you browse the Internet, and things like Android are more sexy and concrete. But Android clearly is just a way to drive ads, not a separate business.

Yes, that's true, when we refer to ads we have to consider both internal properties and external.