The modern music industry's version of a four-leaf clover is the diamond-status album. Sure, some releases still reach that vaunted 10 million mark after several years (or in the case of Linkin Park's Hybrid Theory a dozen) on the charts, but it's an increasingly rare feat.

Which is what makes Adele's 21 all the more special for having achieved the music industry's version of baseball's perfect game. The fact that the Grammy-winning smash did it in its 92nd week on the charts makes the feat even more amazing, since the last album to move that many units in a shorter time span was 'NSYNC's No Strings Attached, which hit 10 milli in its 43rd week in January 2001.

But in an era when YouTube views, concert ticket sales, magazine covers, endorsement deals and product lines, TV appearances and digital single downloads have become the new measures of an artist's success, how did Adele pull it off? And is she the last of a dying breed of [article id="1698032"]mega-sellers?[/article]


"There is no set of events that can be duplicated [with 21]," said Keith Caulfield, Associate Director of Charts/Retail for Billboard magazine. "Every blockbuster album has its own set of unique circumstance that propel it to that status and I don't think anyone would have expected 21 to sell as extraordinarily well as it has."

Like many breakout albums that cross the diamond mark, 21 brewed up a perfect, unique storm: a disc packed with strong, emotional material that resonated with a broad audience, a first single ("Rolling in the Deep") that crossed over to just about every radio genre from pop to rhythmic, top 40 and Latin, a viral sensation that spawned countless YouTube lip dub and parody videos and an ineffable "it" factor about the artist that drew listeners from 8 to 80 into her orbit.

"She's so real and it showed in the few interviews she did ... and whenever people saw here she seemed so legit," said Caulfield of Adele's no-fuss persona. "When you match that personality with the personal stories of her own life told in a song like 'Rolling in the Deep' and 'Someone Like You,' it resonates with the public. When it can be something personal, but still universal, it hits home with people. They're listening to her story, but it could be your own story too."

As the music industry has moved toward a singles-driven, grazing model that's made superstars of everyone from Katy Perry to Justin Bieber and One Direction, 21 is an example of what can happen when you focus on an overall album and sell it as a complete unit, according to Jeff Rabhan, chair of recorded music and an arts professor at NYU's Clive Davis Department of Recorded Music.

The 20-year veteran of the music business, who has worked with everyone from Kelly Clarkson to Linkin Park and Jennifer Lopez, said the thing Adele did that, say Park's Hybrid Theory didn't, was that it reached an older demographic that is much more likely to buy a CD rather than a digital single.

"She benefitted from being ubiquitous and appealing to the widest range of audience possible," he said, noting that Adele did so while doing very few interviews, extremely limited touring and a fraction of the TV and promotional stunts as pop stars like Rihanna and Bieber. Because of her vocal cord surgery, pregnancy and seeming desire to let her songs do the talking, Adele has inserted bit of mystery into a genre where oversharing has become the norm.

"In the digital age, she has proven that word of mouth reigns supreme, more than radio, press or touring," said Rabhan. "People responded to a notion of sincerity and authenticity over a genetically engineered pop star."

Because of the fickle nature of young female fans who love Bieber and 1D today, but might be on to the next one in six months, Rabhan said it's unlikely that a male pop star will breach the gap anytime soon. (It took Usher's 2004 smash Confessions eight years to reach diamond.) But certainly top sellers like Taylor Swift could do it with her mix of strong, relatable lyrics and a deep audience connection. Swift's best selling album to date is Fearless, which has moved more than 6.6 million copies.

"I would never say never because what I love about music is that there's always room for a phenomenon," he said. "People love a Cinderella story and Adele is one."

Caulfield was also unwilling to say that 21 may signal the end of an era, because just a few years ago people wondered if anyone would ever sell one million albums in an opening week and Taylor Swift has done it two times in a row.

"I'm not sure it will be as regular an occurrence as it was in the late 1990s and early 2000s when Vevo and YouTube didn't exist, you couldn't stream anything and the Internet was still young," he said. "Back then if you wanted a song you had to buy the album. Now there's so many ways to consume music, from buying individual songs to streaming them, or just watching a video that it's much harder to sell 10 million albums now than it was 10 years ago."