The singer’s multi-million-selling collection has become the first to pass the 3 million digital sales mark in the US. The milestone was confirmed by Nielsen SoundScan for Rolling Stone after another healthy sales run in 2013. 21 was ironically the 21st best-selling album of 2013 in the US, despite being released just under three years earlier. The record topped the year-end album best-sellers list in both 2011 and 2012 in the US. 21 has sold over 10 million copies in the US alone, while its worldwide sales currently stand around 25 million copies. Adele is reportedly working on the follow-up to 21, which is expected to be released later this year.