[PAR35]

Unless you are a Nielsen family , does not matter what you watch as per tvgrimreaper

Not so.

The big cable companies (AT&T, Spectrum, etc.) pull their own data from the boxes/cards. Then, there are new technologies like Symphony. And more direct competitors like Rentrak and Comscore.

I've not heard of tvgrimreaper, but if that's what they say, they're still living in the 1980s.

[SMGFan]

this info is not provided to Nielsen and billions of dollars are spent based on Nielsen ratings alone.

If you’re not in a Nielsen family, your viewing isn’t measured for TV ratings.

[SMGFan]

Is Nielsen’s neutral 3rd party measurement perfect?
Nope, but those that buy & sell the $70b of US TV advertising find it good enough.
Particularly when non-neutral 1st party measurement produces situations like this:

https://www.mercurynews.com/2018/10/16/facebook-lured-advertisers-by-inflating-ad-watch-times-up-to-900-percent-lawsuit/

https://twitter.com/TVGrimReaper/status/1052586363621584896