NBC’s coverage of the Games is drawing audiences three times bigger than ABC, CBS and Fox combined. But while the relative ratings strength of the coverage remains formidable, the seismic shift toward online viewing has kept the Nielsen numbers from being as big as NBC hoped. The average audience of 27.8 million viewers through the first 10 nights is down 17% from the 2012 Games in London.
Source: NBC’s slumping Olympic ratings show how TV is at a crossroads – LA Times