Adele has had a bit of a quiet 2013 – relatively speaking since she did, you know, win an Oscar, in addition to enjoying her first full year as a mother. She managed to notch another accolade without doing much, though.

Her 2011-released smash '21' is the first album to sell 3 million digital copies. The album, which landed in January (in Europe) and in February (in the U.S.) of 2011, has sold a total of nearly 11,000,000 copies, landing it at the plum spot of No. 13 on SoundScan's best-selling platters since the organization began keeping score in 1991.

Yahoo! reports some intriguing facts and figures. Like the fact that '21' has sold 7,757,000 copies on CD format – which is just under 75% of the total haul. That's interesting, given the rapid decline of the compact disc. The 3 million digital copies accounts for about 28% of the total sold, while 40,000 were sold on vinyl LPs, which tallies less than 1% of the total. We must add that Adele's voice on vinyl must sound like a dream!

Perhaps the fact that so many copies of '21' were sold on CD speaks to Adele's demographic, and proves that most of her fans are of an older demo that still purchases CDs?

Or maybe it's just the fact that '21' is one of those albums that you have to own in hard copy form? Could be!