Re: The elephant in the room...
Freeview itself is, essentially, just a marketing operation for free to air TV. For the vast majority of receivers, they have no way of monitoring what people are watching, because there is no return channel available, or if available actually connected.
The main purpose of Freeview initially was to ease the transition to digital (and, to a degree, to ensure that the primary channels maintained their pre-eminence in a digital landscape).
It's now, especially after some of the escapades of the past, also involved more in helping set standards, to ensure that kit marked with their logo performs in the way expected, and gives a consistent experience for users (channels in the same place, trailer booking works, audio description supported, and so on). But the end game is the same - to ensure there is a free to air TV service built around the PSBs.
The only sense in which Freeview gets money from advertisers is in that it is part-funded by the broadcasters, who themselves get money from advertising, in most cases. In terms of the service they offer to you, the consumer, there is no fee.
You could argue that then that makes you the product, but unlike people who data mine, that's only in the sense that they are delivering your eyeballs to the programmes made by people on the platform.
If Freeview kit was reporting home about what people are watching, I rather think someone would have noticed by now.