After "Breaking Bad" drew 10.3 million viewers to one of the most crowd-satisfying finales in television history on Sunday, Twitter and Facebook raced to tell the news media about the throngs who shared their instant reactions to the show on the social networks.
The companies were seeking more than just bragging rights.
Facebook and Twitter both see the social conversation around television as a way to increase use of their sites and win a bigger piece of advertisers' spending, which eMarketer estimates will be $171 billion across all types of media this year in the United States. In recent months, they have engaged in an escalating battle -- publicly and behind the scenes -- to claim the title of the nation's digital water cooler as they woo networks and advertisers.
Sorting out which site deserves the crown, however, is tricky. Each company uses its own standard for determining social TV conversation, and unlike other types of Internet traffic, there is no neutral arbiter.
Twitter, citing data calculated by Nielsen's SocialGuide service under a confidential formula, said about 600,000 people had posted more than 1.2 million messages, or tweets, about the "Breaking Bad" finale over about a 10-hour period surrounding the East and West Coast broadcasts. But that included retweets, which are messages that simply pass along what others have posted.
Facebook said three million people had chimed in on its service. But that counted original posts, comments on those posts and even "likes," the quick thumbs-up that people can give to a friend's Facebook item. And the service looked at everything in a 24-hour period that included the broadcasts.
The public relations blitz shows how important old-fashioned television has become to the Internet-era social networks, particularly Twitter. The company, based in San Francisco, has signed TV-related deals with dozens of advertisers and content distributors over the last year, like Verizon Wireless and ESPN, to burnish its growth prospects as it prepares to sell stock to the public for the first time. That initial public offering is likely to take place next month.
Neither Facebook nor Twitter has disclosed how much revenue it makes from advertising related to TV, and some industry experts doubt they are earning much.
Still, there is little question that television is a favorite topic for users. About half of Americans visit social networks while watching TV, and one in six Americans posts comments about shows during their broadcasts, according to a coming report by eMarketer, which found that people in some countries like China and India are even more active in their chatter.
Live events like sports attract the highest engagement. "Sports events comprise somewhere between 2 and 3 percent of TV programming in any given month but generate close to 50 percent of the Twitter activity" around TV, said Sean Casey, senior vice president for product at Nielsen's SocialGuide unit.
Nielsen has found that the average audience for Twitter messages about a TV show is 50 times the number of people posting messages about the show. If 2,000 people are posting messages about a show, for example, an average of 100,000 people are seeing those messages. The research firm also found that heavy Twitter activity around a popular broadcast can drive more people to both the show and Twitter.
That kind of potential impact intrigues networks and advertisers, and this week, Nielsen began reporting detailed Twitter activity along with conventional TV audience ratings to its clients.
For viewers, the line between what they see on TV and what they see on their smartphones and tablets is quickly blurring.
During this year's United States Open, for example, the beer maker Heineken sponsored the tennis tournament in New York, the television broadcast and video highlights posted on Twitter, including a remarkable 54-shot rally between Novak Djokovic and Rafael Nadal. Potential viewers could catch up on the matches from anywhere.
"We were trying to bring people to the event who weren't there," said Ron Amram, senior media director at Heineken USA. "All of us have realized how powerful Twitter can be to get the conversation going."
Twitter, considered by many to be the leader in social conversation around live TV, has spent much of 2013 courting networks like Fox and MTV and consumer brands like Heineken. Last week, for example, it signed a deal with the National Football League to distribute football clips sponsored by Verizon Wireless and other companies.
Such partnerships have created a significant new revenue stream for Twitter.
"We've built a business around working collaboratively with TV," said Adam Bain, Twitter's president of global revenue. "We really see our role as a force multiplier."
Although Mr. Bain declined to provide financial details about the initiative, the public may learn more when the company files information for prospective investors, which could occur as soon as this week.
Facebook, whose social platform is built more around each individual's web of relationships than rapid-fire conversation, has a more complicated relationship with TV.
With about 128 million Americans and 699 million people worldwide visiting the site on any given day, the company contends that it has become a mass medium with something that television does not have: a vast amount of information about its users that can be used to finely target advertising pitches.
Emphasizing its ability to reach consumers wherever they are through their mobile devices, Facebook has stepped up its efforts to convince traditional TV advertisers like Microsoft, the Ford Motor Company and Mondelez International, formerly known as Kraft Foods, that its platform can reach their customers more efficiently than TV.
"Marketers want to be where their consumers are," said Carolyn Everson, Facebook's vice president for global marketing solutions. "We are a formidable brand-building platform."
Facebook's most direct challenge to television is yet to come. In the next few months, the company is planning to offer marketers a video ad format that would let them automatically play short clips directly in users' news feeds, with rich links to further information.
"It will allow you to build a canvas around a brand story," said Ritu Trivedi, a managing director of MediaVest, which helps companies create ads and has had preliminary discussions with Facebook about the product.
Even as Facebook competes with television networks for ad dollars, it is also trying to cozy up to them. In recent weeks, it has begun offering networks like CNN and Fox Sports access to publicly posted comments and the ability to search for broad trends.
Facebook is also sending roundups of data similar to the information it released about "Breaking Bad" to the four big broadcast networks.
Privately, Facebook executives acknowledge that they are playing catch-up to Twitter, which has dominated industry thinking about social TV.
Twitter's format -- which presents 140-character comments by its users in a chronological stream but also allows the embedding of photos and video clips -- is well suited to the real-time nature of TV events, according to advertisers and network executives. And over the last year, Twitter has created several tools that make it easier for advertisers to reach its users, including a unique targeting system that can scan a show for specific ads, then display another ad from the same marketer to people posting about the show.
Twitter is also testing ways to highlight to its users the most active conversations about TV shows during prime-time hours.
"Twitter is, in my view, the only social television application that you could say is at critical mass," said Pete Vlastelica, senior vice president at Fox Sports Digital, which is trying out Facebook's new social TV search tools.
Jason Kint, a senior vice president for the CBS Corporation's interactive division until earlier this year, said that real-time conversation about TV was valuable, but he doubted that Twitter and Facebook could meaningfully cash in.
"There's definitely a lot of hype, and maybe one day they'll live up to it all," he said. "But I certainly don't see it taking away ad share from television."
Correction: October 3, 2013, Thursday
This article has been revised to reflect the following correction: An earlier version of this article misstated, because of erroneous information provided by Nielsen, the average audience for Twitter messages about a TV show. The number of viewers of such messages was found to be 50 times the number of people posting the messages (some posters send multiple messages); it is not the case that an average of 50 people see each tweet.interact
This article originally appeared in The New York Times.