The social media impact seems to work best for quirky shows with a small but devoted audience, rather than the popular shows aimed at the large audiences, said Greg March, director of digital media for Wieden+Kennedy. But perhaps social media is changing altogether the notion of what is a massively popular show and what is a niche show.

"There is no possible way that Nielsen ratings are truly capturing what people are watching on television," Tanner said. "The measurement systems we have in place are seriously inadequate."

The IDG News Service