2 Become 1 third chart-topper and their first Christmas number-one single in the UK. It sold 209,000 copies in the first three days of release and 462,000 in the first week, becoming the tenth best-selling single of the year. "2 Become 1" sold 1.14 million copies in total, giving the Spice Girls their second and final million-selling single in the UK.Despite being released during the final two weeks of 1996, "2 Become 1" was the 5th best seller of the year. In Ireland, "2 Become 1" was the group's second number-one single, and their first to debut at the top of the Irish
2 Become 1 the song a "perfect adult contemporary confection". Greg Kot of the "Chicago Tribune" said that their first album "is a compendium of slick secondhand urban pop encompassing [...] G-funk synths on 'Say You'll Be There' [...] and Babyface's guitar and strings balladry on '2 Become 1'". In a review of the group's 2007 compilation album "Greatest Hits", Talia Kraines of BBC Music called it "shimmering" adding that "only a cold heart could fail to love their first festive #1". Digital Spy's Nick Levine said that the group's slower songs were "probably their strongest suit", and thought that "'2 Become 1'