The song is about hardships of single mothers and alludes to the nursery rhyme, Rock-a-bye Baby.
The song became the UK Christmas number one for 2016 on 23 December 2016.
It is the first song in chart history to become Christmas number one after already being at the top of the charts for six weeks.
The video has over 2.2 billion views on YouTube as of December 2019, making it the 30th most viewed video on the site.
Poland (ZPAV) Diamond certification with 100,000 sales.