The track passed a landmark 1 million pure sales (downloads and CD sales) in December 2018, according to the Official Charts Company, and its all-time U.K. streams passes 281 million, making it the most-streamed track released prior to 2010 (it's also recognized as the 12th biggest-selling single of the 2010s). Currently, total U.K. combined sales are 3.52 million.
For chart longevity, no other song comes close. The title for second-best belongs to Snow Patrol, whose 2006 hit "Chasing Cars" has bagged 166 weeks (and counting) on the Official U.K. Singles Chart Top 100, with Ed Sheeran's 2017 release "Perfect" close behind in third place with 165 weeks.
"Mr Brightside" appeared on the band's chart-leading debut album Hot Fuss, released on U.K. indie Lizard King. The LP also featured "Somebody Told Me," "All These Things That I've Done" and "Smile Like You Mean It."