Variations of the question in the headline come up often enough that we figured it’d be better to just do a post answering the question and pointing people to it when it comes up.
The reason you don’t see any regular reporting for Big Ten Network, CBS Sports Network, SEC Network and others is that those nets don’t subscribe to the Nielsen service that would include it in any of the widely distributed daily/weekly reporting.
If you’re wondering why not, the one-size-fits-all answer is that there’s not really any upside for them to subscribe as far as advertising sales. Our experience is that it’s pretty common for new networks and/or networks that aren’t available in most homes to go that route.
Those networks can still order reports from Nielsen but have control over what information, if any, is released, i.e. if Kentucky vs Mississippi State averaged 2 million viewers on the SEC network to lead all of cable sports last night, chances are good that ESPN will issue a press release about that.