[blowfish721]

I don't know about the US but at least here in northern Europe on the broadcasting side this used to be true. Now the monitoring of what people are watching is done through the setup boxes as well as the web streams. When it comes to what commercials being broadcast it's usually done through logging in the software that handles the playlist (for linear tv) and then reported back to the advertisers. The advertisers probably have different systems in place to verify it as well however.