Despite competition from a range of critically acclaimed shows and the NFL, "Breaking Bad" went out with a bang—with 10.3 million viewers tuning in to its series finale, its highest ratings by far. What's remarkable is the show's massive, rapid momentum.
Viewership is up 300 percent over last year's finale, and up from the previous high of just 6.6 million viewers, who tuned in to the second-to-last show a week ago. And that's not all. A one-hour "Talking Bad," a talk show about the scripted series, drew a record 4.4 million viewers.
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To put the AMC show's record in context: "Breaking Bad" had the third most watched series finale in cable history, behind only HBO's "The Sopranos" and "Sex & The City."
And among basic cable programming, "Breaking Bad" had the highest ratings ever. And in contrast to HBO's hits, "Breaking Bad" didn't deliver consistently huge numbers, but instead saw a dramatic rise in viewers into its last shows.
So what does the show's dramatic ascent mean? Critical praise, a cult following on social media and the power of Netflix and DVDs to catch up on allowed more newcomers to get sucked into the show's dark story line.
The show has drawn critical support since launching in 2008, but didn't really take off from a ratings perspective until the end of the fourth season. That season finale delivered 1.9 million viewers, up 23 percent from season three. AMC stretched out the final 16 episodes into two eight-episode runs. Between the first half and the second half of the fifth season, viewer numbers doubled.
What happened? People heard about the show via social media and from friends, and caught up through DVDs, streaming on Netflix or buying episodes on Apple's iTunes. (During the Golden Globes recently, "Breaking Bad" creator Vince Gilligan thanked Netflix for saving "Breaking Bad.") Those viewers in turn shared news of how much they liked the show with their friends on social media, which has a far bigger impact than traditional word of mouth.
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The social media numbers from the finale of "Breaking Bad" show just how valuable and powerful Facebook and Twitter can be as a destination for virtual, water-cooler conversations.
On Twitter, the East Coast and West Coast airings of the finale generated a total of 1.24 million Tweets, with a peak of 22,373 Tweets-per-minute. Meanwhile, Facebook says more than 3 million people generated more than 5.5 million interactions about the show during its finale.
Over the course of the fifth season, when Facebook started tracking the social conversation, Facebook saw more than 23 million "Breaking Bad" related interactions from 11 million users over the course of the final season, before the last episode.
Television doesn't just benefit from social chatter, it's clearly a powerful driver of social conversation, one that both Twitter and Facebook are increasingly capitalizing on.
Just this week, Facebook will start sending regular reports to the TV networks with data on how much conversation—likes, comments and shares—their shows are generating on Facebook. This comes on the heels of Twitter striking a massive TV deal with CBS, allowing the broadcaster to embed its clips and ads on Twitter. Goals include boosting Twitter traffic and CBS ratings.
Viacom was the first to launch such a partnership with Twitter, CEO Philippe Dauman telling CNBC last week that the platform really works to drive both conversation and viewer numbers.
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—By CNBC's Julia Boorstin. Follow her on Twitter: @JBoorstin