From the New York Times:
When Senator Ted Cruz, Republican of Texas, started a 21-hour speech on Sept. 24 to protest President Obama’shealth care law, the average daily rating for C-Span2, the cable channel devoted to Senate proceedings, increased more than fivefold from the day before, according to data provided to The New York Times by Rentrak. As Mr. Cruz kept talking into the next morning, C-Span2 fans kept watching. In fact, the average rating rose a bit higher on Sept. 25, before returning to more normal levels one day later. ...
“We’re pleased to hear it, but it’s news to us,” a C-Span spokesman, Howard Mortman, said when told about the Rentrak ratings. “Noncommercial C-Span doesn’t track numbers. Our operations are funded by cable and satellite affiliates as a public service, and they don’t ask us to report numbers to them.”