Re: North of 85%...
"... Google has almost no market share in actual phones"
True. But for the average Joe who has just bought his Android phone from his outlet of choice, the first thing he's got to do is either create an account with Google, or log in using his existing one. Either way, he is immediately tied (in data terms) to that device, regardless of who made it.
Facebook may be as bad in terms of data slurping, but you're not pushed into anything with them before you can use your shiny new handset.