NEWS - Revolution social! In America la Nielsen (l'Auditel Usa) misurerà da lunedì la classifica dei tweet dei programmi (è la "unique audience", bellezza)! Da noi l'Auditel ha ancora un panel con le prese nei muri per attaccare i decoder (è un Bel Paese per vecchi...)

Articolo di Brian Stelter per il "New York Times"

Only 98,600 people wrote messages on Twitter about the two-hour season premiere of “Grey’s Anatomy” last month. That’s a tiny fraction of the 9.3 million who, according to Nielsen, watched the show that night.

Two episodes of NBC’s “The Voice” ranked in the top 10, reaching 3.8 million and then 2.7 million accounts.

But the posts, 225,000 of them in total, were seen by millions of Twitter users, some of whom might have fired up their digital video recorders or laptops to watch the episode later.

Nielsen is now measuring what it calls the “unique audience” for Twitter posts about television, providing a more complete view of the phenomenon known as social TV. On Monday the company is introducing Nielsen Twitter TV Ratings, a product announced last year that professes to measure all the activity and reach of Twitter conversation about shows, even if it has yet to be embraced by television executives and gain a broad client base.

“We feel this is going to be a credibility-building moment for the industry,” said Andrew Somosi, the chief executive of SocialGuide, an analytics company that Nielsen acquired last November, in part to create the new product.

Measures of posts about a TV show (“Can’t wait for ‘The Walking Dead’ to start”) are just the tip of Twitter’s iceberg, Mr. Somosi said in an interview: “The full iceberg is the extent to which people are seeing those tweets.” For example, the 225,000 posts about the Sept. 26 episode of “Grey’s Anatomy” were seen by 2.8 million distinct Twitter accounts, according to Nielsen’s algorithms.

It is impossible to say how many of those users watched the show as a result of the posts, but previous research has found that Twitter activity sometimes spurs viewership. Twitter has made collaboration with the television industry a priority as it seeks to impress investors; the prospectus for its initial public offering, published Thursday, mentioned television 42 times.

Executives at Nielsen say they expect that TV networks will start to promote their Twitter TV Ratings performance the same way they do broadcast ratings. But it is unclear how many networks or advertisers are actually paying to receive the overnight data. Nielsen declined to name any customers, and representatives of only two media companies — Discovery Communications, the Discovery Channel owner, and the ad-buying giant Universal McCann — were quoted in a news release about the new product.

“This is just the beginning; the data hasn’t been available until now,” said Sean Casey, who founded SocialGuide and is now its senior vice president for product.

During the week of Sept. 23, for example, the finale of AMC’s “Breaking Bad” ranked No. 1 in the Twitter TV Ratings, with 1.2 million posts that reached 9.3 million Twitter accounts, according to Nielsen. Two episodes of NBC’s “The Voice” also ranked in the top 10, reaching 3.8 million and then 2.7 million accounts. Interestingly, one of four new episodes that week of “Jimmy Kimmel Live” cracked the top 10. It was the one broadcast Sept. 26, with a sketch that set off a Twitter feud between Mr. Kimmel and Kanye West.

Mr. Casey said he and his colleagues had a variety of techniques to capture posts about shows and exclude those that merely use similar words. (With the ABC drama “Scandal,” for instance, messages that mention “a scandal” would be thrown out.) In the future they plan to distinguish between a TV star’s posts about his or her own show (which are not currently measured) and posts from viewers, so networks (and presumably talent agents) can tell how influential a star’s posts are.

Some networks may question Nielsen’s methodology, especially since a TV-related post is said to be viewed whenever it is loaded on the Web or whenever it shows up on screen, however briefly, on a mobile device.

More generally, skepticism abounds about how representative Twitter chatter is — or isn’t.

“What people often lose sight of is the fact that the overwhelming majority of conversations about TV shows still take place offline,” said Ed Keller, the chief executive of the Keller Fay Group, a market research firm that specializes in word of mouth and supplies data to networks like CBS.

The firm’s surveys consistently indicate that 80 percent of conversations about TV shows happen in person and 10 percent happen on the phone, with most of the remaining 10 percent occurring online.

“The conversations that take place in the real world can often be quite different from those that take place on social media,” Mr. Keller said.