The 38-year-old singer hasn't done many interviews; she's done even fewer photo shoots. Yet at a time when the promotional mantra appears to be "More is more", Sia's relatively reserved approach is paying off: entered Billboard's album chart at No1. "Woah," she tweeted after the chart news broke, "I can't believe this experiment worked."

Born in Australia and now based in Los Angeles, Sia (whose last name is Furler) first drew widespread attention in the early 2000s as a member of the electro-soul group Zero 7; her solo career later took off after her song was featured in the final episode of HBO's .

But as she explained last year in a so-called "anti-fame manifesto" published in , Sia soon tired of the public scrutiny that accompanies celebrity in the age of TMZ. "Imagine the stereotypical … mother-in-law character … criticising you for an hour straight once a day, every day, day after day," wrote the artist, who had also struggled with addiction.

So Sia turned to writing songs for others - and quickly established herself as a go-to source of sticky hooks and lyrics about overcoming emotional hardship. Among the hits that she helped create: Rihanna's , Beyonce's and by French DJ David Guetta, who ended up using Sia's demo vocals on the finished track instead of a performance he'd solicited from Mary J. Blige.

Sia decided to make another album of her own, her first since in 2010, only after being "pushed into it", according to her manager, Jonathan Daniel. "She's such a great artist that I just thought it'd be something she'd regret if she didn't do it," he says. "And with the success of her writing, she could think of it as Sia's revenge."

Daniel says he negotiated a deal with RCA Records that excused Sia from the usual promotional duties (including touring), an arrangement the label's president, Tom Corson, says he entered into because "Sia is one of the world's best songwriters and singers". The idea, Corson says, is that "she'll do stuff, just not in the usual way. That was fun for us".

Val Pensa, who handles marketing at RCA, remembers an early meeting with Daniel. "He said, 'She wants this blond bob to be the centre of the campaign,'" Pensa recalls. "And we were like, 'We can work with that.'" The haircut is on the cover of , and featured in a performance on the Logo network that Sia did with the New York City Gay Men's Chorus.

The hairpiece was also there on Jimmy Kimmel's head during a gag on his show in which Maddie taught her dance moves from the clip to the host and his similarly bewigged sidekick, Guillermo Rodriguez.

Sia was highly involved in the planning for these events, people close to the singer say. "For , she was doing research about where we could find a mattress thin enough to cut out a hole for her face," Pensa says. "She was very specific about the bed," according to Jeremiah Silva, who books musical talent for Meyers' show. "She knew what she wanted," Silva says.

As precisely detailed as they've been, the stunts have worked in part because they follow the more conventional phase of Sia's career, when she was less reluctant to discuss herself or her work. That means there's a long back story available to anyone whose interest is piqued by the notion of a pop artist putting herself outside pop's personality cult; indeed, Pensa says Sia's "Wikipedia numbers have been through the roof".

"Her background gives this stuff some context," says Corson, pointing out that with a new artist, the same approach "would look a bit gimmicky, wouldn't it?"

Sia's success is the result, too, of a strong record. As eccentric as it is accessible, balances booming beats and top-40-tooled melodies with idiosyncratic textures and vocals that reveal appealing imperfections. Songs such as - in which she asks a lover to "detonate me, shoot me like a cannonball/Granulate me, kill me like an animal" - invite a natural curiosity about the woman singing them.

Greg Kurstin, who produced the album (and has also worked with Pink and Katy Perry), says Sia's signature sound has become "more accepted in the mainstream" as A-list stars continue to record her songs. "It's not easy these days for music to speak for itself," he says. "But it does happen."

Which isn't to say that Sia's label has stopped searching for ways to maintain, and extend, the enthusiasm she's created so far. Given the effectiveness of the campaign, it's not hard to imagine this kind of anti-promotion strategy - one clearly designed to stand out from the look-at-me! crowd - catching on with other artists. The conversation now is "'OK, this is working - great,'" says Corson. "'So what's next?'"