Duffy told the Daily Mail that this retro-soul song, "is about the way my heart rate increases whenever I leave Wales to go to London." (Source Mercy Songfacts). In Feb 2008 'Mercy' stormed to the top spot of the UK charts on download sales alone. This isn't the first taste of success for Welsh songstress Duffy, in 2003 she was runner up in Wawffactor (the Welsh alternative to Pop Idol) and in 2004 she was guest vocalist on electro duo Mint Royale's 3rd album. Read more on Last.fm.