One caveat: CBS Sports Network does subscribe to Nielsen, and they do get audience data. The network chooses not to release the data (based on Comscore numbers I've seen, its ratings are negligible). It's allowable under Nielsen rules and CBS has been doing it for years.
All networks can (and certainly do) order custom reporting, but CBS Sports Network doesn't subscribe to national Nielsen measurement, and as a result, as you note controls the release of info.
One caveat: CBS Sports Network does subscribe to Nielsen, and they do get audience data. The network chooses not to release the data (based on Comscore numbers I've seen, its ratings are negligible). It's allowable under Nielsen rules and CBS has been doing it for years.
All networks can (and certainly do) order custom reporting, but CBS Sports Network doesn't subscribe to national Nielsen measurement, and as a result, as you note controls the release of info.