SocialGuide monitors and analyzes Internet-posted reactions to programs on 232 U.S. television channels, "including Spanish channels," the firms said in a statement.
"Social TV is transforming the consumer viewing experience with more than 33 percent of Twitter users actively tweeting about TV-related content," the statement said.
"The skyrocketing adoption and use of social media among consumers is transforming TV-watching into a more immediate and shared experience. As TV networks see this phenomenon unfold, they require understanding of the impact of social TV on their programming, ratings and advertising effectiveness," said Steve Hasker, president of global media products and advertiser solutions at Nielsen.
NM Incite is a joint venture between Nielsen and McKinsey & Co. The company researches social media, applying its findings to help firms market their brands.